Volume Calculator Guide: Cubic Metres and Litres
Learn how to calculate rectangular volume in cubic metres and litres from length, width and depth.
Volume measures three-dimensional space. For a rectangular object or project area, multiply length by width by depth using consistent units. Cubic metres are especially useful for bulk materials, while litres can make smaller quantities easier to understand.
Measure all three dimensions
Measure length, width and depth. Keep all three in the same unit before multiplying.
Calculate cubic metres
When measurements are in metres, multiply length × width × depth to get cubic metres.
Convert to litres
One cubic metre equals 1,000 litres. Multiply the cubic-metre result by 1,000 when a litre figure is useful.
Connect volume to material planning
Concrete, soil, mulch and gravel are often planned by volume before being converted into litres, bags or approximate weight.
Formula
Volume = length × width × depth. Litres = cubic metres × 1,000.
Worked example
A box measuring 2 m × 1.5 m × 0.20 m has a volume of 0.6 m³, which is 600 litres.
Common mistakes to avoid
- Using inconsistent units.
- Forgetting that depth is part of the calculation.
- Confusing cubic metres with square metres.
- Assuming volume alone determines the final purchase quantity.
Frequently asked questions
What is the formula for rectangular volume?
Multiply length × width × depth using consistent units.
How many litres are in a cubic metre?
One cubic metre equals 1,000 litres.
Why is volume useful for home projects?
Concrete, soil, mulch and gravel are commonly planned by volume before being converted into litres, bags or weight.
Use the Volume Calculator
Enter your project measurements in the calculator, review the result and compare it with the product or supplier information for your specific project.