Estimate how many cubic yards of concrete your project may need before you order. Enter your own measurements for a slab, round pad, strip footing or post holes, add a practical waste allowance, and review cubic yards, cubic feet, cubic metres and an optional concrete-only cost.
Select the project shape, then enter your actual measurements. The calculator converts the volume into cubic yards and also shows cubic feet and cubic metres.
Your cubic yard result will appear after you press Calculate Concrete Yards.
The PDF includes project type, dimensions, waste allowance, base cubic yards, rounded cubic-yard quantity, cubic feet, cubic metres and concrete-only cost.
A cubic yard contains 27 cubic feet. The calculator finds the project volume in cubic feet first, then divides by 27 to convert the result to cubic yards.
The calculator keeps cubic yards, cubic feet, cubic metres, waste allowance and cost easy to compare in one place.
See the main concrete quantity in the unit commonly used for ready-mix ordering in the United States.
Check the underlying imperial volume before and after your selected waste allowance.
Compare the same quantity in metric units for plans, specifications or international references.
Add a percentage for small differences in forms, excavation and site measurements.
Enter your own price per cubic yard to estimate concrete-only material cost.
Save the project measurements and converted concrete quantities for reference.
A Concrete Yard Calculator estimates concrete volume in cubic yards. In the United States, ready-mix concrete is commonly discussed and ordered by the cubic yard, so converting project measurements into yd³ is one of the most useful steps when planning a slab, driveway, patio, footing or group of post holes.
The calculation begins with three-dimensional volume. A surface area such as 100 square feet is not enough by itself because concrete thickness changes the amount of material. A 100 ft² slab at 4 inches thick needs much less concrete than the same area at 8 inches thick. The calculator therefore combines length, width and depth before converting the result to cubic yards.
Cubic Yards = Length (ft) × Width (ft) × Thickness (ft) ÷ 27
If slab thickness is measured in inches, divide it by 12 to convert inches to feet first. A 4-inch slab is 0.3333 ft thick. A slab measuring 10 ft × 10 ft × 4 in has a volume of approximately 33.33 ft³. Divide by 27 and the base volume is about 1.23 yd³ before adding waste.
One yard equals 3 feet. A cubic yard is therefore 3 ft × 3 ft × 3 ft, which equals 27 cubic feet. That is why a concrete volume calculated in cubic feet is divided by 27 to convert it to cubic yards.
| Cubic Feet | Cubic Yards | Cubic Metres |
|---|---|---|
| 9 ft³ | 0.33 yd³ | 0.25 m³ |
| 13.5 ft³ | 0.50 yd³ | 0.38 m³ |
| 27 ft³ | 1.00 yd³ | 0.76 m³ |
| 54 ft³ | 2.00 yd³ | 1.53 m³ |
| 135 ft³ | 5.00 yd³ | 3.82 m³ |
| 270 ft³ | 10.00 yd³ | 7.65 m³ |
When thickness is uniform, you can make a quick check by comparing slab area and depth. The table below shows approximate base cubic yards before waste.
| Slab Area | 4 Inches | 5 Inches | 6 Inches | 8 Inches |
|---|---|---|---|---|
| 50 ft² | 0.62 yd³ | 0.77 yd³ | 0.93 yd³ | 1.23 yd³ |
| 100 ft² | 1.23 yd³ | 1.54 yd³ | 1.85 yd³ | 2.47 yd³ |
| 250 ft² | 3.09 yd³ | 3.86 yd³ | 4.63 yd³ | 6.17 yd³ |
| 500 ft² | 6.17 yd³ | 7.72 yd³ | 9.26 yd³ | 12.35 yd³ |
| 1,000 ft² | 12.35 yd³ | 15.43 yd³ | 18.52 yd³ | 24.69 yd³ |
There is no single waste percentage that works for every concrete project. Formed slabs over a carefully prepared base can be measured relatively accurately, while hand-dug footings and post holes can vary more. Small losses during placement can also affect the final amount required.
The calculator starts at 0% so you deliberately choose the allowance. A 5% or 10% planning buffer is often used in estimating, but the right figure should reflect the real site conditions rather than a fixed online rule.
| Base Cubic Yards | 5% Allowance | 10% Allowance | 15% Allowance |
|---|---|---|---|
| 1.00 yd³ | 1.05 yd³ | 1.10 yd³ | 1.15 yd³ |
| 2.00 yd³ | 2.10 yd³ | 2.20 yd³ | 2.30 yd³ |
| 5.00 yd³ | 5.25 yd³ | 5.50 yd³ | 5.75 yd³ |
| 10.00 yd³ | 10.50 yd³ | 11.00 yd³ | 11.50 yd³ |
A round pad is a cylinder. Enter the diameter in feet and depth in inches. The calculator divides the diameter by two to get the radius, converts the depth to feet, calculates cubic feet and then converts that volume to cubic yards.
Cubic Yards = π × Radius² × Depth (ft) ÷ 27
Because radius is squared, a small change in diameter can make a noticeable difference in volume. Measure the finished form or excavation rather than relying only on an early nominal dimension.
Strip footings use a rectangular volume formula. Enter total footing length in feet and the footing width and depth in inches. The calculator converts the inch dimensions to feet before calculating cubic yards.
If the footing changes width or depth, divide it into separate sections rather than using one rough average. Calculate each section and add the cubic-yard results before applying your final allowance.
Post holes are cylinders. Enter hole diameter and depth in inches plus the number of holes. The calculator converts inches to feet, calculates the total cubic feet and then converts the result to cubic yards. A simple post-displacement percentage can also be applied.
The price field lets you enter your own cost per cubic yard. This creates a concrete-only material estimate based on the volume with waste rather than a fixed national price.
Estimated Cost = Cubic Yards With Waste × Price Per Cubic Yard
Delivery, minimum-load charges, waiting time, pump hire, reinforcement, excavation, formwork and labor may be separate. Use the Concrete Cost Calculator for broader budgeting and the Concrete Order Calculator when supplier minimums and truck loads matter.
| Project Example | Dimensions | Base Cubic Feet | Base Cubic Yards | With 10% Waste |
|---|---|---|---|---|
| Small Slab | 10 ft × 10 ft × 4 in | 33.33 ft³ | 1.23 yd³ | 1.36 yd³ |
| Patio | 12 ft × 12 ft × 4 in | 48.00 ft³ | 1.78 yd³ | 1.96 yd³ |
| Driveway Section | 20 ft × 10 ft × 6 in | 100.00 ft³ | 3.70 yd³ | 4.07 yd³ |
| Footing | 40 ft × 12 in × 12 in | 40.00 ft³ | 1.48 yd³ | 1.63 yd³ |
| Round Pad | 8 ft dia × 4 in | 16.76 ft³ | 0.62 yd³ | 0.68 yd³ |
Square feet describe area, not volume. Concrete ordering must include depth. Two slabs with the same square footage can require very different amounts of concrete if their thicknesses differ. Cubic yards combine all three dimensions into one quantity that can be compared with a ready-mix quote.
Cubic-yard estimating becomes especially useful when a project contains several different concrete sections. A driveway may include a main rectangle, a wider apron and a turning area. A patio may have a rectangular section plus a curved edge. A foundation may combine strip footings with isolated pads. Instead of forcing these into one average dimension, calculate the sections separately and add their cubic-yard totals.
Driveways are commonly estimated from length × width × thickness. A 20 ft × 10 ft section at 6 inches thick contains 100 cubic feet, or about 3.70 cubic yards before waste. If the driveway changes width, calculate each section separately. Use a dedicated Driveway Concrete Calculator when you want a focused driveway estimate.
A rectangular patio can be calculated exactly like a slab. If part of the patio is circular or semicircular, estimate that section separately using the round-pad formula. Combine the volumes only after each shape has been calculated.
Long narrow slabs are sensitive to small width and thickness changes. A 50-foot walkway that ends up several inches wider than planned can add a noticeable amount of concrete over the full length. Re-measure after the forms are installed.
Footing trenches can be irregular, especially when excavated by hand. Measure actual width and depth in several locations. If the trench walls crumble or widen, the real concrete requirement can exceed the nominal drawing volume.
Post-hole volume can accumulate quickly across many holes. A small increase in diameter or depth multiplied by 10, 20 or 30 holes can materially change the total. Use the exact hole count and measure more than one hole when the ground is inconsistent.
The calculator also shows the volume in cubic metres. One cubic yard is approximately 0.7646 cubic metres. This conversion can be useful when comparing imperial measurements with metric drawings, product data or international specifications.
| Cubic Yards | Approx. Cubic Metres | Cubic Feet |
|---|---|---|
| 0.50 yd³ | 0.38 m³ | 13.5 ft³ |
| 1.00 yd³ | 0.76 m³ | 27 ft³ |
| 2.00 yd³ | 1.53 m³ | 54 ft³ |
| 5.00 yd³ | 3.82 m³ | 135 ft³ |
| 10.00 yd³ | 7.65 m³ | 270 ft³ |
| 20.00 yd³ | 15.29 m³ | 540 ft³ |
The Concrete Yard Calculator focuses on volume in yd³. The Concrete Order Calculator goes further into supplier minimums, accepted increments, truck capacity and delivery cost. Use the yard calculator when your main question is “how many cubic yards do I need?” and use the order calculator when you are ready to translate that volume into supplier logistics.
Bagged concrete is often used for small repairs and isolated post holes. Ready-mix is commonly more practical once the volume becomes large. If you want to compare a cubic-yard result with packaged mix, use the Concrete Bags Needed Calculator and enter the manufacturer-stated yield for the product you are considering.
Recalculate whenever dimensions change, especially after excavation or formwork. Early estimates are useful for budgeting, but final ordering should use the best available site measurements. A change of even 1 inch in slab thickness can noticeably affect a large area.
For U.S. workplace safety information related to respirable crystalline silica, see the Occupational Safety and Health Administration. For concrete industry resources and technical education, see the American Concrete Institute. Always follow current project plans, local requirements and supplier instructions for the real job.
The calculator uses the price per yard you enter, but the complete delivered project cost can include additional charges and site work.
Use related calculators for ordering, bag quantities and broader concrete cost planning.
Answers to common questions about cubic yards, cubic feet, slab thickness, waste, footings, post holes and concrete cost.
For a rectangular slab, convert the dimensions to feet, multiply length by width by depth to get cubic feet, then divide by 27 because one cubic yard contains 27 cubic feet.
One cubic yard equals 27 cubic feet.
Yes. Enter length and width in feet and thickness in inches. The calculator converts the thickness to feet before calculating cubic yards.
Yes. Enter your own waste or contingency percentage and the calculator adds it before showing the planning quantity.
Yes. Select Round Pad and enter the diameter, depth and number of identical pads.
Yes. Enter total footing length in feet plus footing width and depth in inches.
Yes. Enter hole diameter and depth in inches and the number of holes. An optional post-displacement percentage is also included.
The fields start at zero so the result is based only on the project measurements and rates you intentionally enter.
Yes. The main result is cubic yards, but the result cards also show cubic feet and cubic metres.
No. The cost uses the price per cubic yard you enter. Delivery, short-load fees, pumping, labour and other project costs may be separate.
Yes. After calculating, you can download a PDF with the project measurements, cubic yards, cubic feet, cubic metres, waste allowance and cost estimate.
Use current project documents, supplier information and official safety guidance alongside any online concrete yard estimate.
Concrete technical education, standards and industry resources.
Visit ACIU.S. workplace information about respirable crystalline silica.
Read OSHA GuidanceConfirm cubic-yard increments, minimum loads, truck capacity, delivery terms and current pricing.
Use the required dimensions, strength, reinforcement and construction details for the actual project.