About the Cubic Feet Calculator
This cubic feet calculator finds the volume of any box-shaped space — a room, a moving box, a storage unit, a raised bed, a fridge or a shipping carton. Enter the length, width and height in whatever unit you measured, add how many identical items you have, and it gives the total in cubic feet along with cubic inches, cubic yards, cubic meters, liters and US gallons.
Use it when comparing moving trucks or storage units (which are sold by cubic feet), checking whether furniture will fit, sizing an HVAC or dehumidifier for a room, or working out how much soil, mulch or concrete fills a space. For bulk materials sold by the yard, the cubic yard figure is what you order.
All three dimensions must use the same unit. If you measured some sides in feet and some in inches, convert first — for example, 18 inches is 1.5 feet.
With the default inputs, the volume is 640 ft³. Change any value above to recalculate instantly.
How to use the cubic feet calculator
- 1Choose the unit you measured in.
- 2Enter the length, width and height using that same unit.
- 3Set the quantity if you have several identical boxes or spaces.
- 4Read the total in cubic feet, plus cubic yards, meters, liters and gallons.
Formula and method
Volume of a rectangular box is length × width × height. Each dimension is first converted to feet (inches ÷ 12, yards × 3, meters ÷ 0.3048, centimeters ÷ 30.48) so the product is in cubic feet, then multiplied by the quantity.
Other units follow from exact conversion factors: 1 ft³ = 1,728 in³, 27 ft³ = 1 yd³, 1 ft³ = 0.0283168 m³ = 28.3168 liters, and 1 ft³ ≈ 7.48052 US gallons. For cylinders or irregular shapes, break the space into boxes or use a dedicated shape calculator.
- L, W, H
- Length, width and height, converted to feet
- ft³
- Cubic feet
Worked examples
10 × 8 × 8 ft room
A 10 × 8 ft room with an 8 ft ceiling holds 10 × 8 × 8 = 640 cubic feet. Dividing by 27 gives 23.7 cubic yards, and multiplying by 0.0283 gives 18.1 cubic meters.
Ten 24 × 18 × 16 inch moving boxes
Each box is 24 × 18 × 16 = 6,912 cubic inches, which is exactly 4 cubic feet (6,912 ÷ 1,728). Ten boxes take up 40 cubic feet of truck space.
2 × 1.5 × 0.5 m raised bed
The bed holds 2 × 1.5 × 0.5 = 1.5 m³ of soil, which is 1,500 liters or about 52.97 cubic feet (1.96 cubic yards).
Frequently asked questions
How do you calculate cubic feet?+
Measure length, width and height in feet and multiply them together. A box 3 ft long, 2 ft wide and 2 ft tall is 3 × 2 × 2 = 12 cubic feet.
How do I get cubic feet from inches?+
Multiply the three dimensions in inches to get cubic inches, then divide by 1,728 (12 × 12 × 12). For example 24 × 18 × 16 in = 6,912 in³ = 4 ft³.
How many cubic feet are in a cubic yard?+
There are 27 cubic feet in a cubic yard, because a yard is 3 feet and 3 × 3 × 3 = 27. Divide cubic feet by 27 to get cubic yards.
How many gallons are in a cubic foot?+
One cubic foot holds about 7.48 US gallons, or 28.32 liters. That is useful for sizing tanks, aquariums and ponds.
How many cubic feet do I need for a moving truck?+
A rough guide is about 150–250 cubic feet of truck space per furnished room. Add up your boxes and large furniture with this calculator for a closer figure.