V = length × width × height
Rectangular prism volume calculator
Multiply length, width, and perpendicular height to find the exact rectangular-prism volume, then convert the cubic result.
Rectangular prism volume formula
V = base area × height = length × width × height
Length and width form a rectangular base. Height is the perpendicular distance to the opposite rectangular face. Multiplying all three dimensions counts the cubic units inside the ideal solid.
Example: length 5, width 4, height 3
The base area is 5 × 4 = 20 square units. Then V = 20 × 3 = 60 cubic units.
Check the third dimension and cubic unit
A rectangle has area, not volume; a rectangular prism also needs a perpendicular third dimension. Use the same length unit for all three inputs, so centimetres produce cm³ and metres produce m³. This models an ideal solid, not the usable capacity of a real container.
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