Litres to cubic metres:
divide by 1,000

How many cubic metres are in a litre?

One litre is 0.001 cubic metres. Put the other way, 1 cubic metre holds exactly 1,000 litres. The litre is defined as one cubic decimetre, a cube 10 cm on each side, and a cubic metre is a cube 100 cm on each side, which fits 10 × 10 × 10 = 1,000 of those small cubes.

Because the relationship is exact, there is no rounding to worry about. Every conversion between litres and cubic metres is a shift of the decimal point three places.

The litres to m³ formula

A second worked example: a domestic swimming pool holds 18,000 litres. Dividing by 1,000 gives 18 m³, which is a figure pool suppliers and local water suppliers often use for chemicals and billing.

1. 1Write the volume in litres.
2. 2Divide by 1000, or move the decimal point three places to the left.
3. 3Label the answer in m³.
4. 4Check the result is smaller than the number you started with.

Chart: litres to cubic metres

Use the table for quick look-ups of common amounts.

Beyond the table, 2000 L is 2 m³, 5000 L is 5 m³ and 10,000 L is 10 m³.

Where litres and cubic metres meet

Households meet this conversion on the water bill. Meters in many countries read in cubic metres, while a bath, a washing machine cycle or a garden butt is described in litres. A household that uses 350 litres a day uses 0.35 m³ per day, which is about 10.5 m³ in a 30-day month.

Builders and engineers use it for tanks, concrete and excavation. A rainwater tank listed as 5,000 L holds 5 m³, and a delivery that fills it from empty is exactly 5 cubic metres of water. A cube of side 1 m would hold the same amount.

Because one cubic metre of water weighs roughly one tonne, the number of m³ is also a quick estimate of the mass of water in tonnes. That is useful when you check whether a floor, trailer or roof can take a full tank.

When you design a tank from its size, work in metres first. A tank 2 m long, 1 m wide and 0.5 m deep has a volume of 1 m³, and that is 1,000 litres. Going from the dimensions to cubic metres and then to litres avoids the three-dimensional mistakes that come from converting each side separately.

Common mistakes when converting litres to cubic metres

• Confusing cubic metres with cubic centimetres. A litre is 1,000 cm³ but only 0.001 m³, so check which unit you want.
• Dividing by 100 because a metre is 100 cm. Volume uses the cube of the length, so the factor is 100 × 100 × 100 ÷ 1000, which comes to 1000 litres per m³.
• Multiplying when you should divide. A cubic metre is a large unit, so the m³ number is smaller than the litre number.
• Reading m3 as m times 3. The small raised 3 means cubed.