Cubic Feet to Tonnes Conversion Guide
Converting cubic feet to tonnes is useful in construction, civil engineering, aggregate handling, soil excavation, concrete estimation and bulk material transport. Unlike conversions between two volume units, changing cubic feet into tonnes requires information about the material being measured.
A cubic foot is a unit of volume. It represents the space inside a cube measuring one foot long, one foot wide and one foot high. A tonne is a unit of mass equal to exactly 1,000 kilograms. Because these measurements describe different physical quantities, there is no universal cubic feet to tonnes conversion factor that applies to every material.
The missing link is density, which describes how much mass a material contains per unit volume. Materials with higher densities produce greater masses for the same cubic-foot volume. For example, ten cubic feet of normal-weight concrete generally has a different mass from ten cubic feet of loose dry soil.
Our Cubic Feet to Tonnes Calculator allows you to select a material or enter your own density. The tool first converts the cubic-foot measurement into cubic metres, multiplies by the selected density in kilograms per cubic metre and divides by 1,000 to express the result in metric tonnes.
You can also calculate the volume represented by a known mass, convert cubic metres into tonnes or estimate tonnes from cubic yards. Additional outputs show kilograms, US short tons and UK long tons, helping avoid confusion between different mass units.
The calculator includes example density presets for several common construction materials. These are starting points for estimates rather than universal specifications. Bulk density changes with grading, moisture, compaction, material composition and the way volume is measured.
Quick answer: Multiply cubic feet by 0.028316846592 to obtain cubic metres. Multiply the cubic metres by material density in kg/m³, then divide by 1,000 to obtain metric tonnes. For 10 ft³ of material at an illustrative density of 2,400 kg/m³, the result is approximately 0.6796 metric tonnes.
In This Guide
- What Is a Cubic Foot?
- What Is a Metric Tonne?
- Why Material Density Matters
- Cubic Feet to Tonnes Formula
- Step-by-Step Conversion
- Material Density Reference
- Conversion Table
- Worked Examples
- Concrete Weight Calculations
- Sand, Gravel and Soil
- Tonnes to Cubic Feet
- Metric, Short and Long Tons
- Common Mistakes
- Frequently Asked Questions
What Is a Cubic Foot (ft³)?
A cubic foot is a unit of volume used in imperial and US customary measurement systems. It describes three-dimensional space, not the mass of the material occupying that space.
Imagine a cube with a length, width and height of exactly one international foot each. The space inside the cube represents one cubic foot.
One international foot equals exactly 0.3048 metres. To convert a cubic foot into cubic metres, cube the linear conversion factor.
This volume relationship is exact. It applies equally to concrete, water, sand, gravel and other substances, provided the quantity being measured is genuinely volume.
Where Are Cubic Feet Used?
Cubic feet are frequently used to describe the capacity of containers, quantities of building materials, air volumes, excavation measurements and certain concrete or aggregate estimates.
They are also useful when measurements are taken in feet. A rectangular space measuring four feet long, three feet wide and two feet deep has a geometric volume of 24 cubic feet.
Cubic Feet and Cubic Yards
One cubic yard contains exactly 27 cubic feet. This relationship comes from one yard equalling three feet.
For larger construction volumes, cubic yards may provide a more convenient unit. If you need to work between those units, see the Cubic Yards to Cubic Feet Concrete Calculator.
Does One Cubic Foot Always Weigh the Same?
No. The cubic foot is a fixed volume, but its contents may have different masses. A cubic foot of dense material has more mass than a cubic foot of lightweight material.
This is why a conversion from cubic feet to tonnes cannot be completed accurately without knowing the density or total mass of the substance.
What Is a Metric Tonne (t)?
A metric tonne is a unit of mass equal to exactly 1,000 kilograms. Its symbol is t. The tonne is commonly used for large quantities of construction materials, cargo, industrial products and other bulk goods.
A metric tonne describes mass rather than volume. For example, one metric tonne of sand and one metric tonne of concrete have the same mass, but may occupy different volumes because their densities are different.
Metric Tonnes and Kilograms
Converting kilograms to metric tonnes is straightforward. Divide the number of kilograms by 1,000.
For example, 750 kilograms equals 0.75 metric tonnes, while 2,500 kilograms equals 2.5 metric tonnes.
Why Are Tonnes Used in Construction?
Tonnes are useful for describing large material masses in purchasing, transportation and handling. A supplier may price aggregate by tonne, while a drawing or site measurement describes the required material in cubic metres or cubic feet.
Converting between volume and mass helps estimate the weight of material associated with a measured quantity. However, the calculation must use a density that matches the material and its condition.
Metric Tonnes Are Not Always the Same as Tons
The word ton can refer to different mass units. The metric tonne contains 1,000 kilograms, the US short ton contains 2,000 pounds and the UK long ton contains 2,240 pounds.
This calculator uses metric tonnes for the primary result and clearly labels US short tons and UK long tons in the detailed results.
Why Density Is Required for Cubic Feet to Tonnes
Density is the quantity that connects volume and mass. It describes how much mass is contained in a particular unit of volume.
When density is expressed in kilograms per cubic metre, multiplying it by a volume in cubic metres produces mass in kilograms.
The resulting kilograms can then be divided by 1,000 to calculate metric tonnes.
Why Different Materials Have Different Densities
Materials differ in composition and internal structure. Concrete contains cementitious binder, aggregate, water and potentially air voids or other constituents. Sand and gravel contain particles with spaces between them, and the amount of water in those spaces may vary.
Even materials with the same general name can have different densities. One batch of gravel may contain a different particle grading or moisture level than another, changing its bulk density.
Bulk Density Versus Particle Density
Bulk density describes the mass of material occupying a total bulk volume, including the spaces between particles. Particle density describes the material making up the individual particles.
For loose sand, soil and gravel, bulk density is usually the relevant value when converting an overall stockpile or container volume into mass.
Using solid-particle density instead of bulk density can significantly overestimate the mass of loose granular material.
How Moisture Changes Material Mass
Water retained in sand, gravel or soil contributes to total mass. Wet material may have a different bulk density from dry material occupying the same volume.
Moisture can also cause changes in the packing or apparent volume of some granular materials. This means the relationship between moisture and bulk density is not always a simple constant percentage.
How Compaction Changes Bulk Density
Compaction can reduce void space and increase the amount of material contained within a given bulk volume. Loose soil and compacted soil should not automatically use the same density.
For construction estimates, distinguish the condition in which the volume is measured: loose, stockpiled, in-place or compacted. These descriptions can materially affect the correct density choice.
Density reminder: Use a density taken from a suitable product specification, material test or supplier statement whenever accurate material mass matters. The calculator presets are examples for preliminary estimates.
Cubic Feet to Tonnes Conversion Formula
The Cubic Feet to Tonnes formula combines an exact volume conversion with a material-specific density. It can be expressed in three stages.
Step 1: Convert Cubic Feet to Cubic Metres
This conversion is exact because it is based on the internationally defined foot.
Step 2: Calculate Mass in Kilograms
Density determines the mass contained in the converted volume.
Step 3: Convert Kilograms to Metric Tonnes
Combining all three stages gives the complete cubic feet to tonnes formula.
Example With Normal-Weight Concrete
Suppose the volume is ten cubic feet and the assumed concrete density is 2,400 kilograms per cubic metre.
Multiply this volume by the selected density.
Divide the kilograms by 1,000.
Ten cubic feet of material at this assumed density therefore has an estimated mass of approximately 0.6796 metric tonnes.
Formula With Pounds per Cubic Foot
If density is provided in pounds per cubic foot, volume and density can be multiplied directly to obtain pounds of mass.
Then convert pounds to kilograms using the exact international avoirdupois pound definition of 0.45359237 kilograms per pound.
The calculator accepts density in either kilograms per cubic metre or pounds per cubic foot and performs the required unit conversion internally.
How to Convert Cubic Feet to Tonnes Step by Step
- Determine the volume. Measure or calculate the material quantity in cubic feet. Make sure the number genuinely represents three-dimensional volume.
- Identify the material. Select the material type or determine which product density should be applied.
- Confirm the density. Use a suitable density in kg/m³ or lb/ft³. Check whether the value represents loose, compacted, wet or dry material.
- Convert cubic feet to cubic metres. Multiply cubic feet by 0.028316846592.
- Calculate kilograms. Multiply the cubic metre volume by density in kg/m³.
- Convert to metric tonnes. Divide the resulting kilograms by 1,000.
- Check the result. Consider whether the calculated mass is reasonable for the selected material and measured volume.
How to Use the Online Calculator
Select the Cubic Feet to Tonnes mode and enter the material volume. Then choose the material that best matches your estimate.
If your material has a documented density, select Custom Density or edit the density field directly. The calculator supports kg/m³ and lb/ft³.
The More Options section allows you to control the displayed decimal precision and add an optional mass-planning allowance. These settings are separate from the base mass calculation.
Press Calculate Tonnes to display the result. The calculator shows metric tonnes, kilograms, US short tons, UK long tons and the related cubic volume measurements.
The result section remains hidden until Calculate Tonnes is clicked. Changing the input volume, selected material, density or other settings hides the previous result.
You can use Copy Result to copy the calculation summary, Reset to restore the starting settings or Swap Units to move between the main cubic-feet and metric-tonnes calculations.
Cubic Feet to Tonnes Material Density Reference
The following table provides illustrative bulk densities for commonly measured materials. These values help demonstrate why the same cubic-foot volume can produce different tonne estimates.
The figures for sand, gravel and soil are examples drawn from published material-density references. The normal-weight concrete and water values are conventional estimating examples. Actual values should be confirmed for the material and condition being assessed.
| Material | Example Density (kg/m³) | Mass for 10 ft³ (t) |
|---|---|---|
| Normal-Weight Concrete | 2,400 | 0.679604 |
| Dry Sand | 1,555 | 0.440327 |
| Wet Sand | 1,905 | 0.539436 |
| Dry Gravel | 1,680 | 0.475723 |
| Wet Gravel | 2,000 | 0.566337 |
| Loose Dry Soil | 1,220 | 0.345466 |
| Water — Approximation | 1,000 | 0.283168 |
Why the Values Are Examples
Material densities are influenced by physical condition. A stockpile of sand does not necessarily match the density of sand compacted into a controlled layer.
For dry and wet materials, moisture content can alter the total mass. Changes in aggregate grading and particle arrangement can also influence how much material is packed into the same volume.
Concrete density depends on the aggregate type, mix proportions and other properties. Lightweight concrete and heavy-density concrete should not use the ordinary 2,400 kg/m³ example without checking the actual product.
Choosing a Custom Density
Custom density is the preferred option when you have a specific technical data sheet, material test or supplier-provided value. Enter the density and select its unit.
For example, if the relevant specification states a bulk density of 1,750 kg/m³, using that value is more appropriate than selecting a generic gravel or soil preset.
The calculator is designed to allow these adjustments without changing the underlying unit relationships.
Cubic Feet to Tonnes Conversion Table for Concrete
The table below illustrates cubic feet to metric tonnes conversion using an assumed normal-weight concrete density of 2,400 kg/m³.
This density is an example rather than a universal property. The tonne values should be recalculated if your actual concrete density differs.
| Cubic Feet (ft³) | Cubic Metres (m³) | Metric Tonnes (t) |
|---|---|---|
| 1 | 0.028317 | 0.067960 |
| 2 | 0.056634 | 0.135921 |
| 5 | 0.141584 | 0.339802 |
| 10 | 0.283168 | 0.679604 |
| 20 | 0.566337 | 1.359209 |
| 25 | 0.707921 | 1.699011 |
| 50 | 1.415842 | 3.398022 |
| 100 | 2.831685 | 6.796043 |
| 250 | 7.079212 | 16.990108 |
| 500 | 14.158423 | 33.980216 |
| 1,000 | 28.316847 | 67.960432 |
Every row uses the same volume conversion factor. Only the material density determines the mass obtained from that volume.
The table should not be used as a universal cubic feet to tonnes chart for sand, soil, gravel, timber or other materials. Enter the appropriate density in the calculator for those substances.
Cubic Feet to Tonnes Worked Examples
These worked examples demonstrate how the same volume can produce different mass estimates depending on the selected material density.
Example 1: Convert 1 Cubic Foot of Concrete to Tonnes
Assume a concrete density of 2,400 kg/m³. First convert one cubic foot to cubic metres.
Multiply by the assumed density and divide by 1,000.
At the assumed density, one cubic foot of concrete has an estimated mass of approximately 0.06796 metric tonnes, or 67.96 kilograms.
Example 2: Convert 5 Cubic Feet of Concrete to Tonnes
Use the same illustrative density of 2,400 kg/m³.
Five cubic feet of concrete at this density has an estimated mass of approximately 0.3398 metric tonnes.
Example 3: Convert 10 Cubic Feet of Concrete to Tonnes
For ten cubic feet, multiply the cubic-foot volume by the exact metric volume factor and the selected density.
The estimated concrete mass is approximately 0.6796 metric tonnes.
Example 4: Convert 25 Cubic Feet of Concrete to Tonnes
Twenty-five cubic feet equals approximately 0.707921 cubic metres.
The estimated mass is approximately 1.699 metric tonnes using the selected example density.
Example 5: Convert 50 Cubic Feet of Concrete to Tonnes
A larger concrete volume can be calculated using the same method.
The result is approximately 3.398 metric tonnes.
Example 6: Convert 100 Cubic Feet of Concrete to Tonnes
One hundred cubic feet is approximately 2.831685 cubic metres.
The estimated mass is approximately 6.796 metric tonnes at the assumed concrete density.
Example 7: Convert 10 Cubic Feet of Dry Sand to Tonnes
Suppose an illustrative dry-sand bulk density of 1,555 kg/m³ is used.
Ten cubic feet of dry sand at this bulk density has an estimated mass of about 0.4403 metric tonnes.
Example 8: Convert 10 Cubic Feet of Wet Sand to Tonnes
For comparison, assume a wet-sand bulk density of 1,905 kg/m³.
The estimated mass is approximately 0.5394 tonnes. The difference illustrates why moisture and the associated bulk density matter.
Example 9: Convert 10 Cubic Feet of Dry Gravel to Tonnes
Assume a dry-gravel bulk density of 1,680 kg/m³.
The estimated mass is approximately 0.4757 metric tonnes.
Example 10: Convert 10 Cubic Feet of Loose Dry Soil to Tonnes
Using an illustrative loose dry soil density of 1,220 kg/m³:
The estimated mass is approximately 0.3455 metric tonnes. Compacting the soil or changing its moisture condition could change the density used for a later calculation.
Example 11: Convert 10 Cubic Feet of Water to Tonnes
Assume an approximate water density of 1,000 kg/m³.
The estimated mass is approximately 0.2832 metric tonnes. Actual water density varies with temperature and other conditions, so this is an approximate physical example rather than a temperature-specific result.
Example 12: Use a Custom Density
Suppose a material volume is 40 ft³ and a product specification provides a bulk density of 1,750 kg/m³.
The estimated mass is approximately 1.9822 metric tonnes. The custom density makes the calculation specific to the chosen material value rather than a generic preset.
Cubic Feet to Tonnes for Concrete
Concrete is one of the most common construction materials for which volume and mass calculations are required. The required concrete quantity for a slab, footing, driveway or other element is normally established from geometry, while the mass may be useful for handling, load planning or related assessments.
A normal-weight concrete density of approximately 2,400 kg/m³ is a common illustrative estimating value. Actual mixes can differ, so use a density from the concrete specification or supplier when greater accuracy is required.
Concrete Slab Volume Example
Suppose a slab measures 10 feet long, 10 feet wide and 4 inches thick. First express thickness in feet.
Multiply the dimensions to determine the geometric volume.
The volume can then be converted into cubic metres or cubic yards. At a density of 2,400 kg/m³, the estimated concrete mass is calculated from the corresponding cubic metre volume.
The slab therefore has an estimated concrete mass of approximately 2.2653 metric tonnes using this example density. The calculation assumes uniform thickness and does not make any structural design recommendation.
If you need the initial slab volume rather than a mass conversion, use the Concrete Slab Calculator to calculate the quantity from the project measurements.
Concrete Volume and Concrete Mass Are Different
Ready-mix concrete is often ordered by cubic metre or cubic yard. A tonne estimate describes mass, not necessarily the supplier's order quantity.
For example, a mass estimate of five tonnes cannot be converted into a concrete order volume without choosing the appropriate concrete density.
Wet Concrete Versus Dry Bagged Mix
The bulk density of finished concrete should not be assumed to equal the relationship between the dry bag weight and the finished volume produced by a bagged product.
Bagged concrete planning normally depends on the manufacturer's stated mixed yield per bag. Two bags with the same nominal weight may produce different volumes because of formulation and mixing requirements.
For that purpose, a Concrete Bag Calculator is more appropriate than dividing the concrete mass by the weight printed on a bag.
Concrete Footings and Foundations
A footing or foundation element may require a mass estimate for handling or other purposes, but the volume must first be calculated from its actual geometry.
The Concrete Footing Calculator can help calculate the geometric concrete volume using relevant dimensions.
Transport and Handling Considerations
Material mass may be relevant when assessing vehicle capacity, storage or lifting arrangements. However, calculating tonnes alone does not establish whether a truck, trailer, crane or supporting structure can safely handle a load.
Safe handling decisions require appropriate equipment ratings, load distribution, actual measured mass and other applicable requirements. Use verified equipment and project documentation rather than a preliminary density estimate as the sole basis for a safety-critical decision.
Cubic Feet to Tonnes for Sand, Gravel and Soil
Sand, gravel and soil are often measured by volume at a site but sold or transported by mass. This creates a need to convert cubic feet into tonnes using bulk density.
Unlike a simple unit conversion, the result depends on material condition. Moisture, particle grading and compaction can all change the mass contained within the same measured bulk volume.
Dry Sand
Dry sand is a granular material with spaces between particles. Its bulk density includes those spaces and can vary with grading and packing.
The example density preset of 1,555 kg/m³ is suitable for demonstrating the calculation, but actual sand should use an appropriate tested or supplier-provided density.
Wet Sand
Wet sand contains water that contributes to overall mass. Moisture may also affect the apparent volume of some sands, so the change in density depends on the material's condition.
The calculator offers a wet-sand example of 1,905 kg/m³. This is an illustrative bulk density, not a guaranteed value for every wet sand.
Dry and Wet Gravel
Gravel density depends on the type of rock, particle size distribution, void space and moisture condition. Dry and wet gravel may have different bulk densities.
The calculator provides example values of 1,680 kg/m³ for dry gravel and 2,000 kg/m³ for wet gravel. Use material-specific data when converting quantities for purchasing or transport.
Loose Dry Soil
Loose soil contains air voids and may occupy a different volume from the same soil after compaction. The calculator includes an illustrative loose dry soil density of 1,220 kg/m³.
A compacted soil density should not automatically be substituted for loose stockpile material, or vice versa.
Excavation Bulking and Swell
Excavated soil may expand when removed from its original position. This means the loose volume in a truck or stockpile can differ from the in-place excavation volume.
A cubic-foot-to-tonne calculation estimates mass from the density and volume supplied. It does not automatically model excavation swelling, settlement or compaction.
For accurate excavation planning, confirm whether your volume is measured in-place, loose or compacted, then use a matching bulk density.
Why Supplier Density Is Better Than a Generic Table
A supplier may know the typical bulk density of the actual material being sold. Test records may also provide more reliable information for a particular project.
Generic tables are useful when beginning an estimate, but should be replaced with material-specific data when the result affects costs, transported weight or project planning.
How to Convert Tonnes to Cubic Feet
The reverse calculation estimates the volume occupied by a known mass. It also requires density because equal masses of different materials can occupy different volumes.
First convert metric tonnes into kilograms by multiplying by 1,000. Divide the mass in kilograms by the material density in kg/m³ to obtain cubic metres.
Then divide cubic metres by 0.028316846592 to calculate cubic feet.
Example: One Metric Tonne of Concrete
Suppose one metric tonne of concrete is estimated at a density of 2,400 kg/m³.
Converting this volume to cubic feet gives approximately 14.7157 ft³.
The result is based on the selected density. A material with lower density would occupy a larger volume for the same one-tonne mass.
When Is Reverse Conversion Useful?
Reverse conversion can be useful when a supplier provides a material mass in tonnes but a project plan requires an estimated volume.
For example, if you have a bulk-material delivery specified in tonnes and need to estimate the space it occupies in a container or stockpile, the density-based calculation can provide an initial volume.
The result should still be checked against practical packing, voids, material condition and the way the volume is defined.
Metric Tonnes vs US Short Tons vs UK Long Tons
The terms tonne and ton are often used in different regions, and they do not always represent the same mass. Confusing them can lead to significant quantity errors.
Metric Tonne
A metric tonne equals exactly 1,000 kilograms. It is commonly used in metric construction, engineering and international trade.
US Short Ton
A US short ton contains exactly 2,000 avoirdupois pounds. Using the defined pound-to-kilogram relationship, it equals exactly 907.18474 kilograms.
UK Long Ton
A UK long ton contains exactly 2,240 avoirdupois pounds, equivalent to 1,016.0469088 kilograms.
Comparison Table
| Mass Unit | Kilograms | Pounds |
|---|---|---|
| Metric Tonne | 1,000 | ≈ 2,204.6226 |
| US Short Ton | 907.18474 | 2,000 |
| UK Long Ton | 1,016.0469088 | 2,240 |
The calculator provides all three mass units in the detailed results. The primary tonne output is explicitly a metric tonne.
Cubic Feet to Tonnes Accuracy and Common Mistakes
1. Assuming a Fixed Conversion Factor
There is no universal number of tonnes per cubic foot. Density must be specified because volume and mass measure different physical properties.
2. Using the Wrong Material Density
A generic concrete density should not be applied to soil, gravel, sand or lightweight concrete. Choose the density appropriate to the material being assessed.
3. Confusing kg/m³ With lb/ft³
Density values expressed in different units cannot be entered as though they are identical. The calculator supports both units and converts them internally.
4. Mixing Metric Tonnes With Short Tons
One metric tonne is 1,000 kilograms, while one US short ton is 907.18474 kilograms. Always check which unit appears in a source document.
5. Ignoring Moisture
Moisture can increase the total mass of materials such as soil, sand and gravel. A dry-density assumption may not be appropriate for a wet material.
6. Ignoring Compaction
A compacted material may have a different bulk density from loose material. Confirm the condition of the material before selecting the density.
7. Using Particle Density Instead of Bulk Density
For loose granular material, bulk density is generally the relevant value for converting the overall occupied volume into mass.
8. Rounding Too Early
Prematurely rounding intermediate volume or density calculations can create avoidable differences, particularly for large quantities.
9. Confusing Material Mass With Concrete Order Volume
Concrete is often purchased by volume rather than tonnes. A calculated mass does not automatically indicate the exact quantity a ready-mix supplier will deliver.
10. Treating Estimated Mass as a Verified Load
A density-based estimate is not a certified weighing result. Actual transport and lifting arrangements should rely on appropriate verified mass information and equipment capacity requirements.
Accuracy reminder: The cubic-foot-to-cubic-metre factor is exact, but the tonne estimate is only as reliable as the chosen material density and the original volume measurement.
Cubic Feet to Tonnes Frequently Asked Questions
How do you convert cubic feet to tonnes?
Multiply cubic feet by 0.028316846592 to obtain cubic metres, multiply by density in kg/m³ and divide by 1,000 to obtain metric tonnes.
How many tonnes are in one cubic foot?
There is no universal answer. The mass depends on the material density. At an illustrative density of 2,400 kg/m³, one cubic foot corresponds to approximately 0.06796 metric tonnes.
Can cubic feet be converted directly into tonnes?
Only when a density or equivalent mass-per-volume value is known or assumed. Cubic feet measure volume, while tonnes measure mass.
How much does one cubic foot of concrete weigh?
At an assumed density of 2,400 kg/m³, one cubic foot has an estimated mass of approximately 67.96 kg. Actual concrete density can differ.
How many tonnes is 10 cubic feet of concrete?
Using an illustrative density of 2,400 kg/m³, ten cubic feet of concrete is approximately 0.6796 metric tonnes.
How many tonnes is 50 cubic feet of concrete?
At a density of 2,400 kg/m³, 50 cubic feet corresponds to approximately 3.398 metric tonnes.
How many tonnes is 100 cubic feet of concrete?
Using the same example concrete density, 100 cubic feet corresponds to approximately 6.796 metric tonnes.
How many tonnes is one cubic foot of sand?
The answer depends on its bulk density and condition. Using an illustrative dry-sand density of 1,555 kg/m³ gives approximately 0.04403 metric tonnes per cubic foot.
How many tonnes is one cubic foot of gravel?
Using an illustrative dry-gravel density of 1,680 kg/m³ gives approximately 0.04757 metric tonnes per cubic foot. Actual density varies.
How many tonnes is one cubic foot of soil?
At a loose dry soil density of 1,220 kg/m³, one cubic foot corresponds to approximately 0.03455 metric tonnes.
What density should I use for concrete?
A density of 2,400 kg/m³ is a common illustrative value for normal-weight concrete. Use a project-specific or supplier-provided density whenever accuracy is important.
How do I convert tonnes back into cubic feet?
Multiply metric tonnes by 1,000, divide by material density in kg/m³, then divide by 0.028316846592.
Can I enter custom density?
Yes. You can enter density in kilograms per cubic metre or pounds per cubic foot.
Does moisture affect the tonne calculation?
Yes. Moisture can change the bulk density and total mass of materials such as sand, gravel and soil.
Is one tonne the same as one US ton?
No. One metric tonne equals 1,000 kg. One US short ton equals exactly 907.18474 kg.
How many kilograms are in one metric tonne?
One metric tonne contains exactly 1,000 kilograms.
How many cubic metres are in one cubic foot?
One international cubic foot equals exactly 0.028316846592 cubic metres.
Can I use the calculator for gravel delivery?
Yes, for a preliminary mass estimate based on known volume and appropriate bulk density. Confirm the supplier's density and actual delivered weight.
Does the optional allowance change the conversion?
No. It affects only the separate mass-planning estimate. The base volume-to-mass calculation is unchanged.
Why are results hidden initially?
The result section remains hidden until Calculate Tonnes is pressed. Changing the inputs hides the previous result to prevent confusion.
Does the calculator support decimal values?
Yes. Non-negative decimal volumes, masses and density values are supported.
Can I calculate concrete bag quantities from tonnes?
Bag quantity planning requires the finished yield of the specific bagged concrete product, not just its nominal dry weight. Use an appropriate concrete bag calculator with manufacturer yield data.
Related Concrete and Material Calculators
Cubic feet to tonnes conversion estimates material mass from volume and density. For concrete projects, the original volume is often calculated from length, width, depth or another geometric shape before a mass estimate is needed.
- Concrete Volume Calculator
- Concrete Slab Calculator
- Concrete Footing Calculator
- Concrete Cubic Foot Calculator
- Concrete Bag Calculator
- Cubic Yards to Cubic Feet
- How We Calculate Concrete
Authoritative Measurement and Density References
The exact unit relationships come from internationally defined measurement units. Example bulk densities should be treated as reference information rather than specifications for every material.
- NIST — SI Units: Volume
- BIPM — International System of Units
- Engineering ToolBox — Dirt and Mud Densities
- Engineering ToolBox — Soil and Rock Bulking Factors
Methodology: The exact cubic-foot factor is 0.028316846592 m³ per ft³. Mass is calculated by multiplying cubic metres by density in kg/m³ and dividing kilograms by 1,000 for metric tonnes. US short tons and UK long tons use their defined masses of 907.18474 kg and 1,016.0469088 kg respectively. Material density presets are illustrative and can be replaced with a custom value. Optional planning allowances and rounding increments are separate assumptions. Actual material quantities and handling loads should be verified using appropriate project-specific data.