A triangle volume calculator computes the 3D volume of a triangular prism — a shape with a triangular cross-section extended through a length. Enter the triangle base, height, and prism length.
A triangle itself is a 2D shape and has no volume — only area (A = ½ × base × height). However, when a triangle is extended through a length to form a triangular prism, the resulting 3D shape has volume.
To calculate "triangle volume," you need the triangular cross-section dimensions (base and height of the triangle) plus the length (depth) the triangle extends through.
V = ½ × base × triangle height × prism length.
This equals: triangle area × prism length = (½bh) × L.
Example: Triangle base 8 cm, height 6 cm, length 15 cm:
V = ½ × 8 × 6 × 15 = 360 cm³ = 0.36 L.
Base 4 m, height 3 m, length 6 m: V = ½×4×3×6 = 36 m³.
Base 4 cm, height 3.5 cm, length 21 cm: V = ½×4×3.5×21 = 147 cm³.
Base 10 m, height 2.5 m, depth 12 m: V = ½×10×2.5×12 = 150 m³.
Base 8 cm, height 5 cm, depth 4 cm: V = ½×8×5×4 = 80 cm³.
35 free volume calculation tools — click any calculator to get started.
Answers to common questions about the triangle volume calculator.
No. A triangle is a 2D shape with only area (A = ½bh). To get volume, the triangle must be extended into a 3D shape — a triangular prism. "Triangle volume" refers to the volume of this prism.
V = ½ × base × height × length = triangle area × prism length. All measurements must be in the same unit.
A trough with triangular cross-section: V = ½ × trough width × trough depth × trough length. For water capacity, convert cm³ to liters (÷1000).
SA = bh + (s₁ + s₂ + s₃) × L where b,h are the triangle base and height, s₁,s₂,s₃ are the triangle's three sides, and L is prism length.
The formula ½bh works for any triangle. For equilateral: h = a×(√3/2). For right triangle: use the two legs as base and height. For isosceles: drop a perpendicular from the apex.