Concrete Volume Calculator
Enter length, width and thickness to get the concrete volume you need and how many truck loads that is.
Quick answer
With the default inputs: Length 6 · Width 4 · Thickness 0.15 etc.Concrete volume (incl. waste) 3.78 m³
Edit the inputs below to recalculate.Inputs
Result
Concrete volume (incl. waste)
3.78m³
| Net volume | 3.60m³ |
| With waste | 3.78m³ |
| Trucks @6 m³ | 1loads |
| Trucks @9 m³ | 1loads |
| Trucks @12 m³ | 1loads |
| C30 cement | 1361kg |
| C30 sand | 1.70m³ |
| C30 gravel | 3.14m³ |
Material quantities are estimated from typical mixes; the laboratory-approved mix design governs.
Reverse: known result, work out one input
Enter a target result; the other inputs stay fixed and this one is worked out.
Formula
| Volume | V = length × width × thickness |
| With waste | V_total = V × (1 + waste %) |
| Truck loads | N = ceil(V_total ÷ truck capacity) |
A 6 m × 4 m × 0.15 m slab: V = 3.6 m³, 3.78 m³ with 5% waste, one 9 m³ truck load.
Concrete grades, typical uses and material reference
| Grade | Typical use | Cement (kg/m³) | Sand (m³/m³) | Gravel (m³/m³) |
|---|---|---|---|---|
| C15 | Blinding, plain footings | 260 | 0.55 | 0.88 |
| C20 | Floors, retaining walls, ordinary footings | 290 | 0.52 | 0.86 |
| C25 | Beams, slabs, columns, ring beams | 320 | 0.48 | 0.85 |
| C30 | Load-bearing structures, most common | 360 | 0.45 | 0.83 |
| C35 | High-rise columns, bridges, precast | 400 | 0.42 | 0.81 |
| C40 | Prestressed and long-span structures | 440 | 0.40 | 0.79 |
Quick volume for common members
| Member | Formula | Example |
|---|---|---|
| Rectangular slab | length × width × thickness | 6 × 4 × 0.15 = 3.6 m³ |
| Rectangular beam | width × depth × clear span | 0.3 × 0.6 × 5 = 0.9 m³ |
| Rectangular column | section L × section W × height | 0.5 × 0.5 × 3 = 0.75 m³ |
| Round column | 3.1416 × radius² × height | 3.1416 × 0.25² × 3 = 0.59 m³ |
| Strip footing | width × depth × length | 1.2 × 0.3 × 50 = 18 m³ |
How to work it out
- Decompose the element into regular blocks: slabs as length × width × depth, beams as width × depth × clear span, columns as section × height less beam depth.
- Break irregular parts — stairs, canopies, toothed construction columns — into their own blocks instead of averaging a thickness.
- Add the net volumes to get the drawn quantity.
- Apply waste by placement method: 1-2% pumped, 2-3% direct discharge, 3-5% barrow work.
- Deduct what is not poured: openings, construction joints poured separately, embedded items and steel sections.
Where it goes wrong
- Double counting beam-column junctions — measure beams to the column face (clear span), not to the centreline, or every floor gains tens of cubic metres.
- Taking slab depth from architectural levels — there is screed thickness between structural and finished level, and 30-50 mm is several cubic metres.
- Forgetting waste — the drawn quantity is the exact-fill number; pump residue, spillage and over-excavation all consume concrete.
Material and cost
Ready-mix typically runs 380-480 per m³ for C25 and 400-520 for C30 including pumping, varying widely by region, with 20-40 per m³ added per grade above C35. Loads under a full truck (8-10 m³) usually attract a part-load charge. Settlement is on the net drawn quantity and the contractor carries the waste — overstate it and you lose money, understate it and you lose the job.
On site
- Order at drawn quantity × 1.02 rather than 1.05 — returning surplus is harder than a small top-up.
- For large pours or long pump runs, check pumping capacity before the trucks arrive.
- On complex levels, measure the actual depth with a level on site; it beats reading the drawing.
Basis
- GB 50666-2011 Code for construction of concrete structures, Chapter 7 (batching, transport, placing and compaction)
- GB 50204-2015 Code for acceptance of concrete structures, Chapter 7 (cast-in-place elements)
- GB/T 14902-2012 Ready-mixed concrete (delivery testing and volume measurement)
FAQ
Why add a waste allowance to concrete volume?
Real pours lose material to spillage, over-excavation, formwork deflection and pump residue. Use 3-5% for slabs and beams, 5-10% for footings, irregular shapes or pumped concrete. Running short mid-pour creates a cold joint, which costs far more than the extra cubic metre.
How do cubic metres and cubic yards convert?
1 cubic yard = 0.7646 m³, so divide m³ by 0.7646 to order in yards. In China 1 方 is exactly 1 m³.
How do I handle columns and round footings?
Round column: V = π × r² × h. Tapered round footing: V = πh/3 × (R² + Rr + r²). This calculator uses a rectangular prism, so for a cylinder compute 3.1416 × radius² × height separately.
Cite this page
Use this format in reports, method statements or coursework. The link is permanent.
Building Calculator. Concrete Volume Calculator. 2026-10-25. https://jianzhujisuan.com/en/concrete-volume
Results are estimating aids only and are not a design basis. Construction and final accounts must follow the drawings, the applicable standards and an approved method statement. Anything affecting structural safety, shoring or falsework must be checked by a suitably qualified engineer.