Calculators
Triangular Prism Calculator
Calculate right triangular prism volume, surface area, base area, and lateral area from three base sides and prism length in your browser.
Measure a right prism with any triangular base.
A right triangular prism has two congruent triangular bases and three rectangular side faces. Enter base sides a, b, c and perpendicular prism length L. Heron’s formula gives base area B = √[s(s − a)(s − b)(s − c)], where s = (a + b + c)/2. Volume V = BL, lateral area = (a + b + c)L, and total surface area = 2B + (a + b + c)L. For base sides 3, 4, 5 and length 10, base area is 6 square units, volume is 60 cubic units, lateral area is 120 square units, and total surface area is 132 square units. The base can be any valid triangle; the prism must be right, with its connecting edges perpendicular to the bases. Use the same unit for every length. Each input must be from 1e-50 to 1e50; scientific notation is accepted. The two shorter base sides must sum to more than the longest. A stable rearrangement of Heron’s formula reduces cancellation, but extremely flat triangles remain limited by browser floating-point precision. Results are rounded to 12 significant digits. All calculations stay in your browser.
Frequently Asked Questions
Everything you need to know about this tool, how it works, and privacy.
Does the base need to be a right triangle?
No. Any three positive sides satisfying the triangle inequality are supported. The prism itself must be right: its connecting edges are perpendicular to its bases.
How do I calculate volume and surface area?
Find triangular base area B with Heron’s formula. Volume is B × prism length. Total surface area is 2B plus base perimeter × prism length.
What is a worked example?
For base sides 3, 4, 5 and prism length 10, base area is 6, volume is 60, lateral area is 120, and total surface area is 132 in the corresponding square or cubic units.
Which units and inputs can I use?
Use one consistent length unit for all four inputs, each from 1e-50 to 1e50. Scientific notation is accepted. Results use 12 significant digits. Degenerate triangles are rejected; extremely flat triangles are limited by floating-point precision. Inputs stay in your browser.