Cubic Feet Calculator

Work out cubic feet for boxes, rooms, fridges and tanks from inches, feet, cm or metres, with cubic metres, litres and US and UK gallons.

Reviewed by Dany, RightSums team · Updated

Runs in your browser. Free, no sign-up.

home-energy · Daily life · UK & US

Enter the length, width and height of a box, room or appliance, or the diameter and height of a tank or drum, in inches, feet, feet and inches, centimetres or metres. Add as many items as you like with a quantity for each, and the calculator totals the volume in cubic feet, cubic inches, cubic metres, cubic yards and litres. It shows US gallons (231 cubic inches, 3.785 litres) and UK gallons (4.546 litres) separately, as they are not the same. Add the inside size of a storage unit, van or room to see what share of the space your items take. Ten boxes of 18 by 18 by 16 inches come to 30 cubic feet.

Accepted inputs

  • Box, room or cylinder shape
  • Lengths in in, ft, ft and in, cm or m
  • Quantity of each item
  • Optional storage unit, van or room size

Outputs

  • Cubic feet and cubic inches
  • Cubic metres and cubic yards
  • Litres
  • US gallons and UK gallons
  • Volume of each item
  • Share of a storage space used

How to use the Cubic Feet Calculator

  1. Choose the unit you measured in, from inches and feet to centimetres and metres.
  2. Add each item as a box or a cylinder, enter its sizes and say how many you have.
  3. The calculator converts every size to metres using exact definitions, works out each volume and multiplies it by the quantity.
  4. It totals the volume in cubic feet, cubic inches, cubic metres, litres and both kinds of gallon, and compares it with a storage space if you enter one.

Frequently asked questions

How do you figure cubic feet?

Multiply length by width by height, all in feet. A room 12 ft 6 in by 10 ft 3 in with an 8 ft ceiling is 12.5 × 10.25 × 8 = 1,025 cubic feet, or 29.02 m³. If you measured in inches, divide the result by 1,728, the number of cubic inches in a cubic foot.

How do I calculate cubic feet from inches?

Multiply the three sizes in inches, then divide by 1,728. A box 18 by 18 by 16 inches is 5,184 cubic inches, which is exactly 3 cubic feet. Ten of those boxes are 30 cubic feet, or 0.85 m³.

How do I convert cm or metres to cubic feet?

Work out the volume in cubic metres, then multiply by 35.315. A box 45 by 45 by 40 cm is 0.081 m³, or 2.86 cubic feet. A space 2.5 m by 2 m by 2.4 m high is 12 m³, which is 423.8 cubic feet.

How many litres and gallons are in a cubic foot?

One cubic foot is 28.317 litres. That is 7.48 US gallons, because a US gallon is 231 cubic inches, or 6.23 UK gallons, because a UK gallon is 4.54609 litres. A drum 30 cm across and 1 m tall holds 70.7 litres, which is 18.7 US gallons or 15.5 UK gallons.

How much storage space do I need for my boxes?

Add up the volume of everything, then compare it with the space. Ten boxes of 18 by 18 by 16 inches are 30 cubic feet, which is 3.75% of a 10 by 10 by 8 ft unit of 800 cubic feet. Packing always leaves gaps, so treat the answer as a minimum and allow more room.

Sources

The rates and rules in this tool come from:

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