Cubic Feet Calculator
Work out a volume in cubic feet — from length, width and depth — with cubic yards, cubic metres, litres and US gallons alongside.
Cubic feet are the everyday volume unit — boxes, rooms, tanks, fridges. This calculator turns three measurements into cubic feet, and then into yards, metres, litres and gallons.
Enter the sides in any unit; the volume comes back in all of them.
Your results
Enter your measurements and press Calculate.
Quantities are rounded up to whole tiles, planks, boxes or bags, after the wastage allowance. Cost appears only when you enter a price.
Formula
All lengths are converted to a single unit before the calculation: 1 ft = 0.3048 m, 1 in = 25.4 mm, 1 ft² = 0.09290304 m², 1 yd² = 9 ft². Material quantities are rounded up — you cannot buy part of a tile, plank or bag.
How to use this calculator
- Enter the length, width and depth.
- Read the volume in cubic feet, yards, metres, litres and US gallons.
- Use the Copy results button to copy the answer.
Worked example
| Box | 5 ft × 4 ft × 2 ft |
|---|---|
| Cubic feet | 5 × 4 × 2 = 40 ft³ |
| Cubic yards | 40 ÷ 27 = 1.4815 yd³ |
| Litres | 40 × 28.316846592 = 1,132.67 L |
| US gallons | 1,132.67 ÷ 3.785411784 = 299.22 gal |
Check it by hand: every step above uses the formula in the box. If your numbers match the example inputs but the calculator gives a different answer, please report it via the contact page.
Frequently asked questions
How many litres are in a cubic foot?
28.316846592 litres. So 40 ft³ is 1,132.67 litres. This calculator shows litres and US gallons alongside cubic feet.
How do I calculate cubic feet?
Multiply length × width × depth, all in feet. A 5 × 4 × 2 ft box is 40 ft³. If your measurements are in inches, divide by 12 first — or enter them here in inches and let the calculator convert.
US gallons or UK gallons?
This page shows US gallons (3.785411784 L). A UK gallon is bigger (4.54609 L). Use the volume converter to convert between them.
What is the difference between this and the cubic yard calculator?
This page leads with cubic feet and adds litres and gallons; the cubic yard calculator leads with cubic yards. The maths is the same — pick the unit you order in.
Related calculators
Estimates only. Results are for planning. Measure twice, confirm box coverage and tile sizes on the packaging you buy, and follow the manufacturer's instructions. See the disclaimer.