What this calculator does
This volume calculator litres tool works out how many litres a rectangular box, tank, fish tank or storage container holds, from its length, width and height. Litres are the practical, everyday unit for anything you fill, from an esky to a water tank, so the result comes back in litres first rather than needing to be converted from a cubic-metre figure afterwards.
To measure volume in litres, multiply length by width by height to get cubic centimetres, then divide by 1,000, since a litre is exactly 1,000 cubic centimetres. Dimensions can be entered in centimetres, metres, millimetres or inches; the calculator converts whichever unit is chosen to centimetres first, so the litres figure is always correct regardless of how the measurements were taken.
The formula
Volume is length multiplied by width multiplied by height, all measured in the same unit. This calculator converts the entered length, width and height to centimetres (if a different unit is chosen), multiplies the three together to get cubic centimetres, then divides by 1,000 to give litres, since 1,000 cubic centimetres is exactly one litre.
| Term | Meaning |
|---|---|
| Litre (L) | A unit of volume equal to 1,000 cubic centimetres, or one thousandth of a cubic metre. |
| Length, width, height | The three internal dimensions of the box, tank or container, each measured independently. |
| Cubic centimetre (cm³) | The volume of a cube one centimetre on each side; 1,000 of them make one litre. |
The inputs explained
| Field | What to enter |
|---|---|
| Length | The length of the box, tank or container. |
| Width | The width. |
| Height | The height. |
| Unit entered | The unit the length, width and height are entered in. |
When to use it
Sizing a fish tank or aquarium
Aquarium capacity is almost always quoted in litres, so measuring the internal length, width and height of a tank gives the figure a fish stocking guide or filter rating expects.
Checking a water tank or container against its rated capacity
A rainwater tank, esky or storage bin often only has its outer dimensions to go on; calculating volume in litres from those measurements checks it against the capacity printed on the label.
Working out how much liquid a container will hold
Before filling a tub, drum or mixing container, calculating its volume in litres avoids under- or over-filling, particularly for anything measured or dosed by the litre.
Worked examples
Every figure in the tables below is produced by this page’s own calculator at build time, so the numbers and the tool always agree. Select any row to load that scenario.
Volume in litres for a range of tank lengths
A spread of tank lengths, with width held at 40 cm and height at 25 cm, each converted to litres.
| Length (cm) | Volume | In millilitres |
|---|---|---|
| 30 | 30.00 L | 30,000 mL |
| 50 | 50.00 L | 50,000 mL |
| 60 | 60.00 L | 60,000 mL |
| 80 | 80.00 L | 80,000 mL |
| 100 | 100.00 L | 100,000 mL |
| 120 | 120.00 L | 120,000 mL |
Volume in litres for common container sizes measured in different units
The same 40 × 25 × 30 box, measured in centimetres, then re-measured in inches to show how the unit choice changes the litres figure for the same physical size.
| Unit entered | Volume | In US gallons |
|---|---|---|
| Centimetres (40 × 25 × 30 cm) | 30.00 L | 7.93 gal |
| Inches (40 × 25 × 30 in) | 491.61 L | 129.87 gal |
Questions
How do I measure volume in litres?
Multiply length by width by height, all in the same unit, to get the volume in that unit cubed, then convert to litres. For centimetres, divide the cubic-centimetre result by 1,000, since 1,000 cm³ equals exactly one litre.
How many litres are in a cubic metre?
Exactly 1,000 litres. A cubic metre and 1,000 litres are the same volume, just expressed in different units, which is why a 1 m × 1 m × 1 m tank holds 1,000 litres.
Does it matter whether I measure in centimetres or inches?
Yes, the unit chosen must match the actual measurements taken. This calculator converts whichever unit is selected to centimetres before working out the litres figure, so choosing the wrong unit for the same numbers produces a very different, incorrect result.
How is calculating volume in litres different from a cubic metre calculator?
The underlying maths is the same, length times width times height, but a cubic metre calculator is built around rooms, freight and bulk material, which are usually large and metric. This calculator leads with litres, the more useful unit for tanks, containers and anything measured by the litre.
For a room, freight load or bulk material instead, see the cubic metre calculator. For volume converted between litres, gallons, pints and other units directly, see the volume converter.