Cubic Metre Calculator
Work out cubic metres (m³) from metres, cm or mm. Then see what that volume weighs in tonnes.
Measure the space
Your answer
1,200 litres · 42.4 cubic feet · 1.57 cubic yards
What it weighs
- MOT Type 12.50 tonnes
- Crusher run2.18 tonnes
- Ballast1.98 tonnes
- Gravel (20 mm)1.92 tonnes
- Slate chippings1.92 tonnes
- Sharp or building sand1.81 tonnes
- Tarmac (laid)2.82 tonnes
- Sand and cement screed (dry)2.52 tonnes
- Topsoil0.96 tonnes
- Bark0.30 tonnes
Stone and sand: as laid, from UK bag weights and coverage. Topsoil and bark: from a 500-litre bag. Wickes says its ballast bag weight can vary by about 5% with wetness.
Quick answers
- The quick way
- Length × width × depth, all in metres, gives m³.
- Litres in 1 m³
- 1,000 litres.
- Cubic feet in 1 m³
- About 35.3 cubic feet, or 1.31 cubic yards.
- Weight of 1 m³
- Type 1 about 2.08 tonnes. Sand about 1.51. Topsoil about 0.8.
How to work it out
- Measure the length, width and depth.
- Change them all to metres. Divide cm by 100, and mm by 1,000.
- Multiply length × width × depth. This gives m³.
4 m × 3 m × 0.1 m = 1.2 m³
1.2 m³ × 1,000 = 1,200 litres
From m² to m³
Know the area in m² already? Multiply it by the depth in metres. That gives m³.
This table does it for common depths. Use the third column for an area of 10 m².
| Depth | m³ per m² | m³ for 10 m² | Litres per m² |
|---|---|---|---|
| 25 mm | 0.025 | 0.25 | 25 |
| 50 mm | 0.05 | 0.5 | 50 |
| 75 mm | 0.075 | 0.75 | 75 |
| 100 mm | 0.1 | 1 | 100 |
| 150 mm | 0.15 | 1.5 | 150 |
| 200 mm | 0.2 | 2 | 200 |
For 30 m², take the 10 m² figure and multiply it by 3.
Litres, cubic feet and cubic yards
Some bags and tanks are sold in litres. Some guides use cubic feet or yards. This table changes them to and from m³.
| Unit | How many in 1 m³ | One of them is |
|---|---|---|
| Litres | 1,000 | 0.001 m³ |
| Cubic feet | 35.31 | 0.0283 m³ |
| Cubic yards | 1.31 | 0.765 m³ |
| Cubic cm (cm³) | 1,000,000 | 0.000001 m³ |
To go from litres to m³, divide by 1,000. To go from m³ to litres, multiply by 1,000.
These come from fixed unit sizes. A foot is defined as 0.3048 m, so the figures don't change.
What 1 m³ weighs
Stone and sand are sold by weight, in tonnes or bulk bags. So you often need to change m³ to tonnes.
- m³ to tonnes: multiply by the weight of 1 m³.
- Tonnes to m³: divide by the weight of 1 m³.
For example, 2 m³ of ballast × 1.65 = 3.3 tonnes.
| Material | Tonnes per m³ | m³ per tonne |
|---|---|---|
| Tarmac (laid) | 2.35 | 0.43 |
| Sand and cement screed (dry) | 2.1 | 0.48 |
| MOT Type 1 | 2.08 | 0.48 |
| Crusher run | 1.82 | 0.55 |
| Ballast | 1.65 | 0.61 |
| Gravel (20 mm) | 1.6 | 0.63 |
| Slate chippings | 1.6 | 0.63 |
| Sharp or building sand | 1.51 | 0.66 |
| Topsoil | 0.8 | 1.25 |
| Bark | 0.25 | 4 |
Stone and sand are as laid, worked out from UK bag weights and coverage. Topsoil and bark are from the weight of a 500-litre bag. Tarmac and screed come from industry data.
Concrete weighs about 2.4 tonnes per m³, says Cemex.
Easy mistakes to avoid
- Mixed units. Change every size to metres first. 100 mm is 0.1 m, not 100. Miss this, and the answer is 1,000 times too big.
- Square and cubic. m² is a flat area. m³ is a space with depth. You can't buy stone by m² alone.
- A "tonne bag" is not a tonne. Wickes bulk bags hold 800 kg. Tippers' hold at least 850 kg. An 800 kg bag of Type 1 is only about 0.38 m³. Of sharp sand, it is about 0.53 m³.
- Packing down. Loose stone takes more room than packed stone. Our Type 1 calculator shows the loose volume too: about 33% more, from a Penn State road guide.
Questions people ask
How do I work out cubic metres?
Multiply the length, width and depth, all in metres. A space 2 m × 1 m × 0.5 m is 1 m³.
How many litres are in a cubic metre?
1,000 litres. A litre is a cube one tenth of a metre wide. So a cubic metre holds 10 × 10 × 10 = 1,000 of them.
How many cubic feet are in a cubic metre?
About 35.3. A foot is defined as 0.3048 m. A cubic metre is also about 1.31 cubic yards.
How do I change m² to m³?
Multiply the m² by the depth in metres. For 20 m² at 50 mm deep: 20 × 0.05 = 1 m³.
How do I work out m³ from cm or mm?
Change each size to metres first. Divide cm by 100 and mm by 1,000. If you already have cm³, divide by 1,000,000.
How many tonnes are in a cubic metre?
It depends on the material. Type 1 is about 2.08 tonnes, sand about 1.51 and topsoil about 0.8. These are worked out from Wickes bag weights and coverage.
How do I work out m³ for a round hole?
Halve the width to get the radius, in metres. Multiply it by itself, then by 3.14, then by the depth. A hole 0.3 m wide and 0.6 m deep is about 0.042 m³, or 42 litres.
How many cubic metres are in a tonne?
Divide 1 by the weight of 1 m³. 20 mm gravel weighs about 1.6 tonnes per m³. So 1 tonne is about 0.63 m³.
Where our numbers come from
- Unit sizes: NIST Handbook 44, Appendix C (1 ft = 0.3048 m; 1 US gallon = 231 cubic inches)
- Type 1 weight and price: Wickes 800 kg bag (checked Oct 2026)
- Crusher run weight: Greenvale Products (1 tonne covers about 11 m² at 50 mm)
- Ballast weight: Wickes ballast bulk bag (800 kg covers 9.7 m² at 50 mm)
- Gravel weight: Wickes 20 mm gravel bulk bag (800 kg covers 20 m² at 25 mm)
- Slate weight: Wickes 20 mm slate chippings bulk bag
- Sand weight: Wickes sharp sand bulk bag (800 kg covers 10.6 m² at 50 mm)
- Building sand weight: Wickes building sand bulk bag
- Asphalt weight: Asphalt Institute (110 lb per square yard per inch)
- Tarmac coverage: Heidelberg Materials asphalt calculator (14–18 m² per tonne at 25 mm)
- Screed: Tarmac Truscreed data sheet (weight once dry; thickness over underfloor heating)
- Topsoil weight: Wickes 500 litre topsoil bag (about 400 kg)
- Bark weight: Wickes 500 litre bark bag (about 125 kg)
- 850 kg bulk bags: Tippers aggregates list
- Packing down: Penn State road-stone guide (8 in loose packs to 6 in)
- Concrete weight: Cemex concrete FAQs (about 2.4 tonnes per m³)
Made by BuildersCount. Last checked 3 Oct 2026.
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