Room Volume Calculator
Room volume in m³, ft³, litres and gallons, plus floor and wall area. Results update as you type.
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Results
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About the Room Volume Calculator
Get a room’s volume in cubic metres, cubic feet, litres and US gallons from its length, width and height, along with the floor area and wall area. It is handy for sizing heating, cooling and ventilation, or for working out air volume.
Enter measurements in metres, centimetres, feet or inches.
The calculation runs in your browser, so the numbers you enter are not uploaded or stored.
Room Volume Calculator example
Length: 5
Width: 4
Height: 2.8Room volume: 56 m³
Volume in cubic feet: 1,977.6 ft³
Volume in litres: 56,000 L
Volume in US gallons: 14,794 gal
Floor area: 20 m²
Wall area: 50.4 m²How it is calculated
Volume is length × width × height, converted to the other units. One cubic metre is 1,000 litres and about 35.31 cubic feet.
Volume = length × width × height1 m³ = 1,000 litres = 35.3147 ft³Floor area = length × width; wall area = 2 × (length + width) × height
How to use the Room Volume Calculator
- Fill in the fields above. Required fields are marked, optional ones can be left blank and fall back to the defaults described on this page.
- Use “Try an example” to see a worked case, then replace the numbers with your own.
- Read the results as you type. The large card is the main answer and the smaller cards are the related figures.
- Copy a single value or everything, or share a link that keeps your inputs.
Room Volume Calculator FAQ
How does the room volume calculator work?
Volume is length × width × height, converted to the other units. One cubic metre is 1,000 litres and about 35.31 cubic feet.
Can I use this to size an air conditioner?
Volume is one input, but cooling needs also depend on sun exposure, insulation, windows, occupants and appliances, so use the room volume as a guide and follow the manufacturer’s sizing advice.
Does it work for irregular rooms?
Split an L-shaped room into rectangles, calculate each one and add the volumes.
Is this room volume calculator free and private?
Yes. It is free with no sign-up, and the calculation happens on your device, so your numbers are never sent to a server.
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