How to use the volume calculator
Choose a rectangular box or cylinder and enter dimensions in the same unit. Volume is three-dimensional, so the result is in cubic units.
Volume formulas
If all dimensions are in feet, the result is cubic feet. Converting cubic units requires cubing the linear conversion factor.
Example: Leo measures a storage box
Leo measures a rectangular box as 10 inches long, 8 inches wide, and 6 inches high. Volume is 10 × 8 × 6 = 480 cubic inches.
Use internal dimensions to estimate usable capacity. This result describes geometric volume, not how tightly irregular objects will fit inside.
Volume formulas for boxes and cylinders
A rectangular box or rectangular prism uses length x width x height. A cylinder uses pi x radius squared x height.
All dimensions must use compatible units. Mixing inches and feet in the same formula without conversion produces a result with no meaningful cubic unit.
Cubic volume is not automatically gallons or liters
The result is expressed in cubic units based on the dimensions entered. Converting cubic inches, cubic feet, or cubic centimeters into gallons or liters requires a separate unit conversion.
For a container, internal dimensions are usually more relevant to capacity than external dimensions because wall thickness occupies space.
Assumptions and limitations
What the estimate assumes
Does not calculate capacity in gallons or liters automatically.
Volume Calculator FAQs
Why is volume measured in cubic units?
Volume uses three dimensions, so the measurement unit is multiplied three times.
How do I calculate box volume?
Multiply length, width, and height.
How do I calculate cylinder volume?
Multiply pi by radius squared and by height.
Can I mix inches and feet?
Convert all dimensions to the same unit before calculating.
How do I calculate the volume of a box?
Multiply length by width by height using consistent units. The result is expressed in cubic units.
General geometry calculator. Use consistent measurement units.