What is the formula for the surface area of a regular tetrahedron?

The surface area equals √3 multiplied by the edge length squared: SA = √3 × a². This comes from the fact that a regular tetrahedron has four equilateral triangular faces, each with area (√3/4) × a².

Does this calculator work for irregular tetrahedra?

No. This tool is for regular tetrahedra only, where all four faces are congruent equilateral triangles and all six edges are equal in length. For an irregular tetrahedron you would need to calculate each triangular face separately.

What units can I use?

You can enter the edge length in millimeters, centimeters, meters, inches, or feet. The result is shown in the corresponding square unit (e.g., cm²).

How is a tetrahedron different from a pyramid?

A tetrahedron is a specific type of pyramid with a triangular base and three triangular side faces — four triangular faces in total. A general pyramid can have any polygon as its base.

What is the relationship between edge length and surface area?

Surface area scales with the square of the edge length. Doubling the edge length quadruples the surface area, since SA ∝ a².

Surface Area of a Tetrahedron Calculator

Enter the edge length of a regular tetrahedron and instantly get its total surface area.

Input

Enter the edge length of a regular tetrahedron.

Edge Length (a)

Formula

SA = √3 × a²

where a is the edge length

Result

Enter an edge length and click Calculate.

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Summary

A regular tetrahedron is a 3D solid with four equilateral triangular faces, all of equal side length. Its surface area is the combined area of all four faces. This calculator applies the formula SA = √3 × a², where a is the edge length, giving an exact and instant result for any positive edge value.

How it works

Enter the edge length of the regular tetrahedron.
Select the unit of measurement (mm, cm, m, in, ft).
The calculator applies the formula SA = √3 × a².
The total surface area is displayed instantly with the selected unit squared.
Use the step-by-step breakdown to verify the calculation.

Use cases

Students solving geometry or solid-geometry homework.
Engineers calculating material needed to cover a tetrahedral structure.
Architects designing tetrahedral decorative elements.
Teachers preparing worked examples for class.
Game developers computing 3D mesh surface areas.
DIY makers estimating paint or foil coverage for pyramid shapes.

Frequently Asked Questions

Last updated: 2026-05-23 · Reviewed by Nham Vu