Estimate how much ready-mix concrete you may need before requesting a quote or booking delivery. Enter metric project dimensions for a slab, footing, beam or cylindrical pour, add your own waste allowance and supplier rounding increment, then estimate cubic metres, truck loads and concrete-only cost in Australian dollars. The calculator keeps quantity, order rounding and service fees separate so each assumption is easy to review.
Select the geometry that best matches your project. The calculator converts the dimensions into cubic metres, then applies the waste allowance and order rounding you choose.
Your result will appear after you press Calculate Ready Mix Concrete.
The displayed order quantity is rounded up using your selected supplier increment. If a minimum order is entered, the cost uses the greater of the rounded quantity or supplier minimum.
The most reliable workflow separates exact geometric volume from waste allowance, supplier order rounding and any minimum-load or service-fee rules.
The calculator keeps physical concrete demand, ordering rules and cost assumptions separate so you can review each number before speaking with a supplier.
See the exact geometric concrete quantity before adding contingency or supplier rounding.
Add a project-specific percentage for excavation, formwork and site variability.
Round up to the increment used by the supplier you are dealing with.
Estimate load count only when you enter the confirmed capacity you want to model.
Enter the quoted A$/m³ rate and optional service fees rather than a fixed online price.
Save the main quantity, order and cost assumptions with ConcreteCreek.com branding.
A Ready Mix Concrete Calculator converts project dimensions into the cubic metres used for planning and ordering premixed concrete. The maths is usually straightforward; the more important challenge is making sure the dimensions represent the concrete that will actually be poured. Slab thickness, footing width, beam depth, post-hole diameter and irregular excavation can all change the final quantity.
In Australia, concrete suppliers commonly discuss ready-mix or premixed concrete quantities in cubic metres. Boral's current concrete calculator likewise presents estimated volume in m³ and describes cubic metres as the standard unit for ordering. The calculator on this page follows the same metric-first approach but adds editable waste, order rounding, truck-capacity and cost fields so the estimate can be adapted to a real supplier quote.
Volume (m³) = Length (m) × Width (m) × Depth (m)
The most common mistake is mixing metres and millimetres without converting them. If a slab is 100 mm thick, use 0.10 m in the multiplication. A 6 m by 4 m slab at 100 mm thick has a base volume of 6 × 4 × 0.10 = 2.40 m³ before any allowance is added.
Ready-mix pricing, delivery fees and truck scheduling matter only after the physical volume is understood. Begin by modelling each concrete shape. A rectangular slab is length × width × thickness. A strip footing is total length × width × depth. A round footing, pier or cylinder uses π × radius² × depth. If drawings or estimating software already provide the volume, use Known Volume mode.
Complex projects should be divided into simple sections. A house slab can include slab panels, edge beams, internal beams, patios, porch areas and separate footings. Treating the entire footprint as one uniform slab can miss a large amount of concrete in deepened sections.
Slab mode is useful for driveways, patios, shed slabs, garage floors, pathways and rectangular pads where the thickness is reasonably consistent. Measure the inside dimensions of completed formwork where possible. If the slab contains rebates, thickenings, steps or beams, calculate those elements separately rather than increasing the whole slab thickness.
For slab-specific planning, use the Concrete Slab Estimator or Concrete Thickness Calculator alongside this ready-mix page. The calculator does not decide what slab thickness is structurally appropriate.
Strip footings and rectangular beams use length × width × depth. Width and depth are often given in millimetres, so the calculator converts them to metres before multiplying. If several identical footings repeat, enter their quantity. If dimensions change around the building, calculate each size separately.
The current NCC Housing Provisions Part 4.2 covers footings, slabs and associated elements and ties footing and slab construction to site classification and other design requirements. Quantity software cannot choose the correct footing size for the site. Use the dimensions shown on the approved drawings or supplied by the appropriate professional. For a more detailed shape-specific take-off, use the Concrete Footing Calculator.
A cylinder uses π × radius² × height or depth. The calculator asks for diameter, divides it by two to obtain radius, then multiplies by depth and quantity. This method can be used for round pads, piers and other cylindrical pours when the dimensions represent the actual concrete.
For structural columns, use the Concrete Column Calculator because column projects often need separate rectangular and circular options. For post holes, remember that a timber or steel post can displace some concrete volume.
If an engineer, estimator, BIM model or supplier schedule already gives a base concrete volume, use Known Volume mode. The calculator then skips geometry and applies only the waste allowance, manual extra volume, order rounding, truck-load estimate and cost assumptions.
This can be useful when comparing supplier quotes because the same physical quantity can be tested against different A$/m³ rates, service fees and minimum-order rules without changing the original take-off.
There is no universal waste percentage that fits every pour. Perfect formwork over a carefully prepared base can be measured closely. Hand-dug trenches, rough excavation, multiple post holes and irregular ground are less predictable. Low spots, over-excavation and form movement can increase concrete demand beyond the neat drawing volume.
The calculator deliberately leaves the waste field empty. Add a percentage only after considering the actual site. It also provides a separate manual-extra field so you can distinguish a percentage contingency from a known additional volume such as an extra 0.20 m³ requested by the concreter.
The calculated volume with waste may contain many decimal places, but suppliers may use specific order increments or operational rules. The calculator can round up to 0.01, 0.05, 0.10, 0.20 or 0.50 m³. This is not a claim that every supplier accepts every increment. Select the increment that matches the supplier you are dealing with.
Rounding up is important because rounding down can leave a pour short. If a project needs 3.64 m³ after allowance and the supplier orders in 0.10 m³ increments, the planning quantity becomes 3.70 m³. Confirm the final quantity and any minimum-load requirements directly with the supplier.
Small ready-mix orders can be subject to minimum quantities, short-load fees or other service conditions. Instead of hard-coding one national rule, the calculator includes an optional minimum-order field and a separate service-fee field. If you enter a minimum order larger than the rounded physical quantity, the cost calculation uses the minimum quantity while still showing the actual rounded order requirement separately.
Always read the supplier quote carefully. A low A$/m³ rate can be misleading if delivery, small-load, waiting, environmental, toll, weekend or after-hours charges are added separately. Use the service-fee field to capture charges that you know apply to the order.
Concrete agitator capacities vary by fleet, vehicle configuration, legal loading, project access and supplier practices. The calculator therefore does not assume one universal truck capacity. Enter the confirmed m³ capacity you want to model. The tool then divides the billed/order quantity by that capacity and rounds up to an estimated number of loads.
Truck-load count is only a logistics estimate. A supplier may choose partial loads, split loads, different vehicle sizes or a delivery sequence that does not match your simple capacity assumption. Use the result to understand scale, then confirm the actual dispatch plan.
Cost is calculated from the billed quantity multiplied by the A$/m³ rate you enter, plus the service fees you enter. The page does not use a fixed national ready-mix price because concrete prices change by location, strength, mix design, aggregate, admixtures, quantity, delivery distance and market conditions.
Estimated Cost = Billable m³ × Quoted A$/m³ + Entered Service Fees
Pump hire, labour, excavation, base preparation, formwork, reinforcement, placing, finishing, curing and testing are not automatically included. For broader budgeting, use the Total Concrete Cost Calculator.
CCAA publishes an Ordering Premixed Concrete datasheet and notes that customers need to be specific because projects can involve different designer specifications and supplier products. Quantity is only one part of the order. Depending on the project, the supplier may need information about strength grade, slump, aggregate size, exposure or durability requirements, additives, colour, delivery time and placing method.
Use the actual project specification rather than guessing mix properties from an online calculator. If the drawings specify a particular concrete, quote that specification accurately when requesting prices and placing the final order.
Cubic metres answer how much concrete is required; MPa answers a different question about concrete strength. The NCC Housing Provisions include concrete requirements for certain footing and slab applications and reference AS 3600 within those provisions. The correct strength, slump and other properties depend on the project.
Do not assume that the lowest-cost standard mix is suitable simply because the volume is correct. Structural, exposure and durability requirements can change the concrete specification without changing the geometry.
The current NCC footing and slab provisions state that water must not be added to increase slump beyond the specified value in the relevant concrete provisions. Site crews should not use extra water as a casual fix for difficult placement or delayed discharge. Follow the project specification and supplier instructions.
If placement requires a different workability, line-pump mix or other property, discuss that requirement before the truck is dispatched. Changing the concrete on site can affect performance and compliance.
Ready-mix concrete has a limited workable delivery and placement window. CCAA describes concrete as a material that needs to be produced close to where it is used, and its concrete overview notes that concrete generally has a relatively short period before it starts to harden. The NCC explanatory information for relevant footing and slab provisions also discusses complete truck discharge timing unless an appropriate retarder is specified.
Practical implication: do not order until the site is ready. Formwork, reinforcement, service penetrations, access, labour, pump setup and finishing equipment should be organised before delivery. Delays can create waiting charges and quality risks.
A volume calculation does not tell you whether a concrete truck can safely reach the pour. Consider road access, gate width, overhead obstructions, ground bearing, turning space, slopes and the distance between truck discharge and the placement area. If direct chute placement is not possible, a pump, conveyor, buggy or other handling method may be required.
CCAA's technical-publication library includes a Safe Site Delivery Checklist developed to assist concrete suppliers with safe discharge to concrete pumps. Site logistics should be discussed with the supplier and pumping contractor before delivery day.
Pumping can make a difficult site easier to place, but it introduces its own requirements and costs. The pump type, line length, setup location, access, priming, washout and concrete mix suitability need coordination. The ready-mix volume itself usually remains based on the project geometry, but pump priming and operational considerations should be discussed with the pump operator and supplier.
Do not simply add a generic pump volume to every order. If the pumping contractor recommends a specific allowance, enter that known amount in the manual-extra field so it remains visible in the estimate.
Hot weather can accelerate setting and increase evaporation. CCAA's technical publications include hot-weather concreting guidance, and the NCC Housing Provisions contain temperature-related requirements within relevant residential footing and slab provisions. On hot days, pour planning, delivery timing, crew readiness and curing become especially important.
The calculator does not adjust volume for temperature. Weather affects construction planning rather than the geometric quantity. Confirm hot-weather procedures with the project team and concrete supplier.
Heavy rain can change excavation size, soften the base, create standing water or damage formwork. Re-measure trenches and forms after significant weather if site conditions have changed. Ordering from old dimensions after an excavation has widened can leave the pour short.
Do not treat standing water or uncontrolled site moisture as part of the concrete mix. Prepare the pour area as required by the project documentation and good construction practice.
A driveway is usually a straightforward slab-volume calculation only if thickness is uniform. Vehicle crossings, thickened edges, drainage details and transitions can add concrete. Calculate those areas separately where necessary. The Concrete Driveway Calculator is useful when the project is specifically a driveway.
If work affects a public footpath, road reserve or crossover, check current local council requirements before arranging trucks, pumps or traffic control.
Landscaping projects can contain irregular geometry. Use the Concrete Walkway Calculator for paths, the Concrete Pool Deck Calculator when a pool opening must be subtracted, and the Concrete Steps Calculator for solid stepped concrete.
Calculate the combined cubic metres first, then return to this page if you want to apply one supplier rate, one order increment and one set of delivery fees to the total.
Bagged concrete can be practical for post holes, repairs and very small pads. As volume increases, the number of bags, manual mixing time and handling effort rise quickly. Ready-mix delivery is often more practical for continuous pours when site access and project scale justify it.
If you are comparing bagged material with delivered concrete, use the Quikrete Bags Calculator or another product-specific bag calculator with the exact manufacturer yield. Do not compare bag prices and ready-mix prices without converting both options to the same finished volume.
| Project Example | Dimensions | Base Volume | With 7% Allowance | Rounded To 0.10 m³ |
|---|---|---|---|---|
| Small Slab | 4 m × 3 m × 100 mm | 1.20 m³ | 1.284 m³ | 1.30 m³ |
| Garage Slab Example | 6 m × 6 m × 100 mm | 3.60 m³ | 3.852 m³ | 3.90 m³ |
| Strip Footing | 20 m × 300 × 300 mm | 1.80 m³ | 1.926 m³ | 2.00 m³ |
| Round Pad | 2.4 m dia × 150 mm | 0.679 m³ | 0.727 m³ | 0.80 m³ |
| Known Volume | 5.00 m³ scheduled | 5.00 m³ | 5.35 m³ | 5.40 m³ |
These examples show quantity maths only. They do not state that the example dimensions, thicknesses or concrete specifications are suitable for any particular structure. Use the actual project requirements.
Every numeric field starts empty. The softened zero is a placeholder only and is not stored as a real value. If you type 6 into a length field, the calculator receives 6 rather than 06. If you type 100 into a thickness field, it receives 100 rather than 0100. Typed values are always clear and unblurred.
Resetting the calculator clears all numeric entries and restores the blurred placeholder state. This prevents leading-zero problems while still making empty fields visually obvious.
Fresh ready-mix concrete delivery is only one part of a concrete project. Later cutting, grinding, drilling, chasing or jackhammering of hardened concrete can generate respirable crystalline silica dust. Safe Work Australia identifies concrete cutting, angle grinding, jackhammering and chiselling among construction activities that can generate silica dust. Quantity planning should therefore sit alongside proper work-health-and-safety planning for any later processing of the concrete.
Do not rely on an online volume calculator for silica controls. Use current Safe Work Australia guidance, the applicable state or territory regulator, safety data sheets and the controls required for the specific work activity. If a contractor will saw-cut joints, drill anchors or grind the finished slab, those tasks should be included in the project safety planning rather than treated as an afterthought.
Supplier quotes are easiest to compare when the physical quantity and concrete specification are held constant. If one quote is based on 4.2 m³ and another on 4.8 m³, the total price difference may be caused partly by quantity rather than a better rate. Reconcile the m³ first, then compare the concrete rate, delivery fee, small-load charge, pump-related mix requirement, waiting-time rules and other services.
Also check whether a quoted rate is before or after GST and whether the stated price covers only concrete supply or includes another service. The calculator keeps the A$/m³ rate and service fees separate for this reason. It gives you a simple place to reproduce each quote on the same volume basis without pretending that all supplier pricing structures are identical.
Early estimating is useful for budgeting, but the most valuable quantity check often happens after formwork, excavation and base preparation are complete. Measure the real pour space again. Check footing widths at several locations, confirm slab thickness control points, measure any widened trenches and add beams or thickened sections that were not part of the first rough estimate.
If the recalculated volume differs materially from the original estimate, update the supplier before delivery rather than hoping the earlier number is close enough. A transparent final take-off reduces the risk of running short mid-pour or paying for significantly more concrete than the project can accept.
Volume, strength, slump, aggregate, exposure class, admixtures and placing method are separate parts of the concrete order.
Use geometry to estimate how much concrete the project physically contains.
Use the strength grade required by the design, specification or applicable project documents.
Workability belongs to the concrete specification and placing method, not the volume formula.
Truck access, pump setup, timing and discharge conditions must be coordinated before delivery.
Answers to common questions about cubic metres, waste, truck loads, minimum orders, concrete rates and ready-mix delivery.
For a rectangular pour, multiply length in metres by width in metres by depth in metres. Add any project-specific allowance and round up according to the ordering increment confirmed by your supplier.
Ready-mix concrete is commonly ordered in cubic metres. Boral's current Australian concrete calculator likewise presents estimated order volume in m³.
There is no universal percentage. The appropriate allowance depends on formwork accuracy, excavation, low spots, irregular geometry and site conditions. Confirm the final quantity with the concreter and supplier.
Yes. Choose the supplier increment you want to model, such as 0.10 m³, and the calculator rounds the quantity upward rather than downward.
Truck capacities vary, so the calculator does not assume one value. Enter the capacity confirmed by your supplier if you want an estimated load count.
Only if you enter them in Delivery / Service Fees. Supplier minimums and small-load charges vary and are not hard-coded.
Yes. If the entered minimum is greater than the rounded physical quantity, the cost calculation uses the minimum billable/order quantity while still showing the rounded project quantity.
No. Pump hire is separate unless you manually include it in the service-fee amount. Labour, formwork, reinforcement, excavation and finishing are also separate.
Yes for rectangular strip footings or beams. For more detailed footing shapes, use the dedicated Concrete Footing Calculator.
Yes, Round / Cylinder mode estimates cylindrical volume. For detailed structural-column planning, use the Concrete Column Calculator.
The blurred zero is only a placeholder and is not a real value. Typing 100 produces 100 rather than 0100, and typed values remain clear.
No. Concrete specification must come from the applicable drawings, engineer, builder, standards or supplier requirements.
Do not alter the specified concrete casually. Relevant NCC footing and slab provisions state that water must not be added to increase slump beyond the specified value. Discuss workability requirements with the supplier before delivery.
Use current supplier information, CCAA technical guidance and applicable NCC provisions alongside any online ready-mix estimate.
Industry guidance explaining why customers need to be specific about requirements when ordering premixed concrete.
View Ordering GuidanceComprehensive Australian guidance covering specifying, ordering, manufacture, supply, handling, placing, curing and site practices.
View Concrete GuideCurrent Housing Provisions covering site classification, concrete, reinforcement and footing/slab construction within their scope.
View NCC ProvisionsAustralian supplier reference confirming cubic metres as the standard quantity unit for concrete planning and ordering.
View Supplier CalculatorNational guidance on respirable crystalline silica hazards from concrete cutting, grinding, drilling and related construction work.
Read Silica Guidance