Cubic Feet Calculator

Find the volume of a box, room, container, or cylinder in cubic feet. Enter all dimensions in one unit and get exact conversions to cubic yards, cubic meters, liters, and cubic inches.

Shape

Dimension unit

LengthftEnter a length greater than zero

WidthftEnter a width greater than zero

HeightftEnter a height greater than zero

QuantitycountMultiplies the volume of identical shapes.Enter a whole number from 1 to 1,000,000

Calculation Results

Total volume

—ft³

Volume of all identical shapes combined.

How to calculate cubic feet

Choose the correct shape

Use rectangular for boxes, rooms, trailers, and bins. Use cylinder for round tanks, pipes, drums, or tubes.

Use one unit for every dimension

Select inches, feet, yards, centimeters, or meters. Changing units converts the current entries so the represented physical size stays the same.

Measure internal or external dimensions intentionally

Use internal measurements for usable capacity and external measurements for occupied space or shipping volume.

Multiply identical items

Set quantity above one when every object has the same dimensions. For different sizes, calculate each separately and add the results.

Cubic feet formulas

Cubic feet measure three-dimensional space. Each input is first converted to feet, the geometric volume is calculated, and quantity is applied before the result is converted to other volume units.

Rectangular volume = Length × Width × Height

Cylinder volume = π × (Diameter ÷ 2)² × Height

Total volume = Volume of one shape × Quantity

Do not mix dimension units manually. Select the unit that applies to all fields and let the calculator perform the conversions at full precision.

Cubic volume conversion table

Starting volume	Cubic feet	Cubic meters	Liters
1 cubic foot	1	0.028316846592	28.316846592
1 cubic yard	27	0.764554857984	764.554857984
1 cubic meter	35.31466672	1	1,000

Methodology, assumptions and sources

All length inputs are converted to feet before geometry is applied. The calculator uses the international foot, defined as exactly 0.3048 meter, and preserves conversion precision until the result is displayed.

Sources:

NIST Handbook 44, Appendix C (2026) — cubic-inch, cubic-foot, liter, and cubic-meter relationships.
NIST SP 811, Appendix B — exact international yard and foot definitions.

Last reviewed: August 2026. Geometry assumes straight rectangular sides or a true circular cylinder.

Frequently asked questions

How do I calculate cubic feet from inches?

Convert each dimension from inches to feet by dividing by 12, then multiply length × width × height. Equivalently, multiply dimensions in inches and divide cubic inches by 1,728.

How many cubic feet are in a cubic yard?

There are exactly 27 cubic feet in one cubic yard because a yard is 3 feet and 3 × 3 × 3 = 27.

How many liters are in one cubic foot?

One cubic foot equals exactly 28.316846592 liters based on the international foot definition.

Should I use inside or outside measurements?

Use inside dimensions for storage or liquid capacity. Use outside dimensions for occupied space, freight volume, or clearance planning.