Concrete Volume Calculator

Length times width times thickness gives cubic metres. Bag count is estimated at seven 40 kg bags per cubic metre.

Your numbers

Length(m)Width(m)Thickness(cm)

Volume

1.5m³

Cement bags

Weight

3,600kg

Formula

Volume = Length × Width × Thickness ÷ 100

Concrete runs about 2,400 kg/m³. The real bag count varies with the mix ratio and aggregate.

What to enter

Input	Default	Accepted range
Length (m)The measurement across, side to side.	5	0 and up
Width (m)The measurement front to back.	3	0 and up
Thickness (cm)How thick one layer is; times the number of layers gives the whole.	10	0.5 and up

Step by step

FormulaVolume = Length × Width × Thickness ÷ 100

With the default numbersVolume = 5 × 3 × 10 ÷ 100

AnswerVolume = 1.5 m³

Quick reference table

Results when only Length (m) changes and everything else stays put.

Length (m)	Volume (m³)	Cement bags	Weight (kg)
2.5	0.75	6	1,800
3.75	1.125	8	2,700
5	1.5	11	3,600
7.5	2.25	16	5,400
10	3	21	7,200

What each result means

Result	At default values
Volume (m³)The space a solid holds — length cubed.	1.5
Cement bagsBags of cement needed, based on 40 kg a bag.	11
Weight (kg)Weight in tonnes; one tonne is 1,000 kg.	3,600

Common mistakes

Concrete runs about 2,400 kg/m³. The real bag count varies with the mix ratio and aggregate.

Glossary

Length: The measurement across, side to side.
Width: The measurement front to back.
Thickness: How thick one layer is; times the number of layers gives the whole.
Volume: The space a solid holds — length cubed.
Cement bags: Bags of cement needed, based on 40 kg a bag.
Weight: Weight in tonnes; one tonne is 1,000 kg.

Frequently asked questions

QHow is Concrete Volume Calculator calculated?

Volume = Length × Width × Thickness ÷ 100 — Length times width times thickness gives cubic metres. Bag count is estimated at seven 40 kg bags per cubic metre.

QCan you walk through an example?

With Length 5m, Width 3m, Thickness 10cm, the answer is Volume 1.5m³.

QWhat do I need to enter?

Enter Length, Width, Thickness. The result recalculates as you type, and an empty box counts as zero.

QHow much does the answer move if I change a number?

Changing only Length (m) moves the answer to Length (m) 2.5 → Volume (m³) 0.75 and Length (m) 10 → Volume (m³) 3. The table below lays out five steps.

QHow are the numbers rounded?

Money is shown to the nearest whole unit, percentages to one decimal place and everything else to two. What you see is rounded; the calculation itself carries the unrounded value forward.

QAnything to watch out for?

Concrete runs about 2,400 kg/m³. The real bag count varies with the mix ratio and aggregate.

Related calculators

Room Area CalculatorFloor area of a room in square metres and Korean pyeong.Room Volume CalculatorInterior volume from length, width and ceiling height.Paint Quantity CalculatorHow much paint you need from wall area and number of coats.Tile Count CalculatorNumber of tiles needed from floor area and tile size.

Keep your length units consistent across inputs — mixing centimetres and metres throws results far off.