Triangular Prism Volume Calculator
The volume of a triangular prism — the area of its triangular end multiplied by its length.
A prism has the same cross-section all the way along, so its volume is always base area × length.
How the triangular prism volume calculator works
A prism has the same cross-section all the way along, so its volume is always base area × length. For a triangular end that is ½ × base × height × length. It is the shape of a roof space, a ridge tent and a toblerone, and the same reasoning gives the volume of any prism whatever its cross-section.
Formula: cone ⅓πr²h; pyramid ⅓lwh; torus 2π²Rr²; hemisphere ⅔πr³; ellipsoid ⁴⁄₃πabc
Worked examples
| Inputs | Volume | Note |
|---|---|---|
| Triangle 6 × 4, length 20 | 240 | 240 |
| A roof space 8 m wide, 3 m high, 12 m long | 144 | 144 m³ |
| A ridge tent 2 × 1.2 by 3 m | 3.6 | 3.6 m³ |
FAQFrequently asked questions
What is the volume of a triangular prism?
The area of the triangular end times the length: ½ × b × h × L.
Which height is the triangle height?
The perpendicular height of the triangular end, not the sloping side or the length of the prism.
Does this work for other prisms?
The principle does — any prism is cross-sectional area times length. Only the area formula changes.
How do I find a roof space volume?
Use the span as the triangle base, the ridge height as the triangle height, and the building length as the prism length.
What if the ends are not triangles?
Work out the end area separately and multiply by the length.
Where these figures come from
- NIST Digital Library of Mathematical Functions — reference definitions for elementary and special functions
- Wolfram MathWorld — definitions and formulas for every topic on this page
- NIST/SEMATECH e-Handbook of Statistical Methods — the statistical formulas (mean, variance, z, confidence intervals, sample size)
- Australian Curriculum (ACARA) — Mathematics — the terms and methods taught in Australian schools
Last checked: September 2026. Formulas are fixed by mathematics and do not change with tax years or regulations.