Volume of Triangular Prism Calculator

Volume = (½ × Base × Triangle Height) × Prism Length

A Triangle, Extended Straight Through

Slide a triangle along a straight path and it sweeps out a triangular prism — the shape behind tents, chocolate-bar packaging, and roof trusses. Its volume calculation is really two steps in one: work out the triangular base area first, then extend it along the prism's length.

The Formula

Triangle Area = ½ × Base × Triangle Height
Volume = Triangle Area × Prism Length

Worked Example

For a triangular prism with base 6, triangle height 4, and prism length 10:

Triangular prism volume, step by step
StepCalculationResult
Triangle area½ × 6 × 412
Volume12 × 10120

Where This Matters

  • Roof truss design — the triangular cross-section of a gable or truss extended along a building's length.
  • Packaging — triangular-prism cartons (the classic Toblerone shape) size their contents this way.
  • Optics — triangular prisms used to split or redirect light are specified by these same dimensions.

How to Use This Calculator

  1. Enter the Triangle Base.
  2. Enter the Triangle Height (perpendicular to that base).
  3. Enter the Prism Length (the extrusion distance).
  4. Select Calculate to get the volume.

Related Calculations

For any other base shape, use the general Prism Volume Calculator, or find just the triangle's area with the Triangle Area Calculator.