How to Calculate Volume Step by Step

Step 1: identify the shape

A box, cylinder, sphere, cone, prism, and pyramid each use a different formula. If the object is irregular, split it into simpler parts or use the closest shape as an estimate.

Step 2: write the formula

Box: V = length x width x height
Cube: V = side^3
Cylinder: V = pi x r^2 x h
Sphere: V = 4/3 x pi x r^3
Cone: V = 1/3 x pi x r^2 x h
Pyramid: V = 1/3 x base area x height
Prism: V = base area x length

Step 3: convert units before multiplying

Use one unit system before calculation. If a problem gives feet and inches, convert them first with the Length Converter.

Step 4: substitute and calculate

Length = 10 ft
Width = 4 ft
Height = 3 ft
Volume = 10 x 4 x 3 = 120 cubic feet

Radius = 1.5 m
Height = 6 m
Volume = pi x 1.5^2 x 6 = 42.41 cubic meters

Radius = 5 cm
Volume = 4/3 x pi x 5^3 = 523.60 cubic centimeters

Example: cubic yards from area and depth

Area = 180 square feet
Depth = 4 inches = 0.333 feet
Volume = 180 x 0.333 = 59.94 cubic feet
Cubic yards = 59.94 / 27 = 2.22 cubic yards

For this workflow, use the Square Feet to Cubic Yards Calculator or Cubic Yard Calculator.

How to check your answer

• Did you choose the right shape?
• Are all measurements in the same unit?
• Did you use radius instead of diameter?
• Did you include the cubic unit?
• Does the number feel reasonable?