Concrete Delivery Load Calculator
Work out how many ready-mix concrete truck loads you need for a pour, including a waste allowance and the size of the final part-load. Add a price per cubic metre for a quick material-cost estimate. It is metric-first and assumes a standard agitator truck (about 8 m³ full), which you can change to match your supplier's fleet.
Enter Values
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How to use this calculator
- Enter the required concrete volume V in cubic metres (m³) — the net volume of your slab, footing or column from a volume calculator.
- Leave the waste allowance at the default 5% for a typical job, or raise it for rough ground, hand-excavated footings or pumped work.
- Set the truck capacity to your supplier's full agitator load (default 8 m³), or a smaller mini-mix size for tight jobs.
- Optionally enter a price per m³ to see an indicative material cost, then read off the number of truck loads, ordered volume and last-load size.
How it works
Ordered volume = required volume × (1 + waste/100). The number of truck loads is ceil(ordered volume ÷ truck capacity), rounding up because you cannot order a fraction of a delivery, and the last load carries whatever is left over: ordered volume − (loads − 1) × capacity. For example V = 20 m³ with 5% waste gives an ordered volume of 21 m³; at 8 m³ per truck that is ceil(21 ÷ 8) = 3 loads, with a final load of 21 − 16 = 5 m³.
Worked example
Worked example. A slab needs 20 m³ of concrete. With a 5% waste allowance the ordered volume is 20 × 1.05 = 21 m³. Using 8 m³ agitator trucks, loads = ceil(21 ÷ 8) = 3, made up of two full 8 m³ loads plus a final 5 m³ load. At $180/m³ the indicative material cost is 21 × $180 = $3,780.00 (excluding part-load fees, pump hire, delivery and GST).
Common mistakes
- Ordering the net design volume with no waste allowance, then running short near the end of the pour.
- Forgetting that a small last load often attracts a part-load or short-load ('cartage') fee, so a 0.5 m³ tail can cost far more per cubic metre than a full truck.
- Assuming every truck is 8 m³ — agitator and mini-mix trucks vary, so confirm the actual capacity with the batching plant.
- Treating the price-per-m³ figure as the full delivered cost; it is material only and excludes pump hire, delivery, additives, part-load fees and GST.
Frequently asked questions
How big is a concrete truck load?
A full agitator (ready-mix) truck typically carries around 8 m³ in Australia, though some run 6–7 m³ and mini-mix trucks deliver roughly 1.5–6 m³. The default here is 8 m³ — change it to match your supplier's fleet.
What waste allowance should I use for concrete?
About 5% is a common allowance for spillage, over-excavation, pump priming and slab-thickness tolerance. Increase it for hand-dug footings, uneven subgrade or pumped pours where more is lost in lines and hoppers.
What is a part-load or short-load fee?
Suppliers usually charge extra for loads below roughly 4–6 m³ because a truck run is not fully utilised. A small final load can therefore cost much more per cubic metre — it is often cheaper to round a pour up to a full load or combine pours.
Does the cost estimate include delivery and pumping?
No. The estimate is ordered volume × price per m³ for the concrete only. It excludes part-load fees, pump or line hire, delivery/cartage, additives and GST, so always get a written quote from the plant.
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