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Litres & liters calculator
Convert cylinder dimensions straight into litres and cubic metres, working from millimetres, centimetres or metres.
This litres & liters calculator takes centimetre, millimetre or metre measurements and returns a clean volume in litres, along with millilitres and cubic metres. It is the quickest way to size a tank, aquarium or container in metric units.
Using the calculator
- Measure across the circular end — the diameter or radius.
- If you measured the diameter, halve it to get the radius r.
- Square the radius and multiply by π to get the base area.
- Multiply the base area by the height h: V = π r² h.
- Convert the result into your preferred unit above.
Worked example. Take a cylinder with a diameter of 10 cm (so a radius of 5 cm) and a height of 25 cm. The base area is π × 5² = 78.54 cm², and multiplying by the height gives a volume of about 1.96 litres (1,963 cm³ · 0.52 US gallons).
| From | To | Multiply by |
|---|---|---|
| cm³ | litres | 0.001 |
| litres | m³ | 0.001 |
| in³ | US gallons | ÷ 231 |
| ft³ | US gallons | 7.4805 |
| ft³ | litres | 28.3168 |
For anything that holds liquid, measure the inside of the cylinder — the wall takes up space that the contents cannot.
Every litres & liters page
Each page below targets a specific question and opens with the calculator ready to go: