Trades

Concrete Volume Calculator

Trades

Concrete Volume Calculator

Live answer1.32 m³base volume 1.2 m³ before 10% allowance

Length (m)Measure the planned pour length in metres.Width (m)Measure the planned pour width in metres.Depth (mm)Enter slab or footing depth in millimetres.Waste allowance (%)Optional allowance for uneven ground, spillage, over-excavation and ordering tolerance.

Live result1.32 m³base volume 1.2 m³ before 10% allowance

Formula used

Depth in metres = depth millimetres ÷ 1,000. Base volume = length × width × depth. Concrete with allowance = base volume × (1 + waste percent ÷ 100).

This is the method behind the answer, so the result can be checked rather than simply trusted.

Live math canvas

Your numbers, formula and explanation together

Concrete Volume Calculator: 1.32 m³. base volume 1.2 m³ before 10% allowance

Formula applied

The exact method behind this answer

CalculationTime keeps the method visible so the number can be checked instead of blindly trusted.

Depth in metres = depth millimetres ÷ 1,000. Base volume = length × width × depth. Concrete with allowance = base volume × (1 + waste percent ÷ 100).

Apply the formulaDepth in metres = depth millimetres ÷ 1,000. Base volume = length × width × depth. Concrete with allowance = base volume × (1 + waste percent ÷ 100).1.32 m³base volume 1.2 m³ before 10% allowance

Your live breakdown

Current inputs in the calculation

These values come from the controls above and update when the calculator changes.

Length: 4 m
Width: 3 m
Depth: 100 mm
Waste allowance: 10 %

Resulting answer

1.32 m³

base volume 1.2 m³ before 10% allowance

Answer: 1.32 m³
Live support: base volume 1.2 m³ before 10% allowance

Assumptions used

What this answer assumes

Volume estimate only. Confirm mix, delivery minimums and structural requirements before ordering.

Length and width are entered in metres and depth is entered in millimetres.
The pour is treated as a rectangular prism with a consistent average depth.
Waste allowance is a planning input only; it is not a building-code, engineering or supplier standard.
The result does not check reinforcement, sub-base preparation, slump, strength grade, delivery minimums or structural design requirements.

Master’s Tip

How to use the result well

Master’s Tip: measure the average finished depth separately from the excavation depth. For real orders, round up after checking site variation, formwork, sub-base level, pump/driver advice, minimum delivery quantities and whether part loads are practical.

Printable record

What belongs in the saved calculation

Save the inputs, result, formula, assumptions, page URL and date together so the calculation can be reviewed later.

Length: 4 m
Width: 3 m
Depth: 100 mm
Waste allowance: 10 %

What-if check

Depth and allowance sensitivity

Small depth changes can move the order quantity. Keep the neat measured volume separate from the allowance you choose for site tolerance.

Depth	Volume with allowance	Change
75 mm	0.990 m³	-0.330 m³
100 mm	1.320 m³	Current depth
125 mm	1.650 m³	+0.330 m³

Allowance	Order estimate	Extra over base
0%	1.200 m³	0.000 m³
5%	1.260 m³	0.060 m³
10%	1.320 m³	0.120 m³
15%	1.380 m³	0.180 m³

Visual proof

Slab prism

The prism shows why depth must be converted to metres before multiplying the three dimensions into cubic metres.

Visual grid

This result measures part of the space you live in

Length, area, volume and material estimates are grid problems too: measure the space, account for edges and allowances, then turn the pattern into a number you can use.

Micro-timehours, minutes, shiftsHuman scaledays, weeks, projectsMacro-timemonths, years, calendars

Measured output1.32 m³

Space calculations turn a real surface, room, run or volume into cells, edges and allowances that can be quoted, ordered or checked.

1.32 m³base volume 1.2 m³ before 10% allowance

Inputs

Length: 4 m
Width: 3 m
Depth: 100 mm
Waste allowance: 10 %

Method

Depth in metres = depth millimetres ÷ 1,000. Base volume = length × width × depth. Concrete with allowance = base volume × (1 + waste percent ÷ 100).

For a 4 m by 3 m slab at 100 mm depth: depth = 100 ÷ 1,000 = 0.10 m. Base volume = 4 × 3 × 0.10 = 1.20 m³. With 10% allowance, 1.20 × 1.10 = 1.32 m³.

Assumptions

Length and width are entered in metres and depth is entered in millimetres.
The pour is treated as a rectangular prism with a consistent average depth.
Waste allowance is a planning input only; it is not a building-code, engineering or supplier standard.
The result does not check reinforcement, sub-base preparation, slump, strength grade, delivery minimums or structural design requirements.

Notes

Use this space on the printed report for client, supplier, classroom, job-location, measurement, quote or approval notes.