The exact equivalent
A cubic metre is exactly 1,000 litres. A litre is defined as a cubic decimetre, and there are 1,000 cubic decimetres in a cubic metre.
1 m³ = 1,000 l
1 l = 0.001 m³
How to convert it by hand
Just multiply by the conversion factor. To go from cubic metres to litres, multiply by 1,000; to come back, divide by that same number or multiply by 0.001.
For example: 25 m³ × 1,000 = 25,000 l.
A tip that saves mistakes: check the result goes the way you expect. If litres are a smaller unit than cubic metres, the number has to come out bigger. If it comes out smaller, you divided when you should have multiplied.
Conversion table
| m³ | l |
|---|---|
| 1 | 1,000 |
| 2 | 2,000 |
| 5 | 5,000 |
| 10 | 10,000 |
| 20 | 20,000 |
| 50 | 50,000 |
| 100 | 100,000 |
Reference points to picture it
| Reference | Equals |
|---|---|
| A cubic metre | 1,000 l |
| A month of household water | 12 m³ = 12,000 l |
| A bathtub | 0.15 m³ = 150 l |
| A car fuel tank | 0.05 m³ = 50 l |
The trick for doing it in your head
Move the decimal point three places right. Nothing to approximate.
It is fine for getting by without a phone, but not for anything that depends on precision: in a recipe, on a building site or in a dose, use the exact conversion.