Tetrahedron Volume

Calculate regular tetrahedron volume using V = a^3/(6sqrt2). Free online 3D geometry calculator with surface area, height, face area, and composition chart.

Calculate tetrahedron volume

About This Calculator

This Tetrahedron Volume Calculator computes the volume, surface area, height, face area, and surface-area-to-volume ratio of a regular tetrahedron -- a Platonic solid with 4 equilateral triangle faces. Simply enter the edge length and get instant results with a visual breakdown chart showing all properties of the tetrahedron.

The calculator uses the formula V = a^3/(6sqrt2) for volume, derived from the general pyramid volume formula V = (1/3) x base area x height. Since a regular tetrahedron has all edges equal, its height is H = sqrt(2/3) x a and its base area is (sqrt3/4) x a^2. Substituting these into the pyramid formula gives the simplified tetrahedron volume formula. The surface area is computed as SA = sqrt3 x a^2, which is the area of all 4 equilateral triangle faces combined.

A regular tetrahedron is the simplest of the five Platonic solids. All four faces are congruent equilateral triangles, all six edges have the same length, and all four vertices are equidistant from the center. This makes the tetrahedron a highly symmetric shape with important applications in geometry, chemistry (methane molecule), engineering (space frame structures), and computer graphics (3D mesh generation using tetrahedral elements).

Properties of a regular tetrahedron:

  • 4 faces (all equilateral triangles)
  • 4 vertices, 6 edges (all equal length)
  • Volume: V = a^3/(6sqrt2)
  • Surface area: SA = sqrt3 x a^2
  • Height: h = a x sqrt(2/3)
  • Face area: FA = (sqrt3/4) x a^2
  • Surface area to volume ratio: SA:V = 6sqrt6 / a
  • Insphere radius: r_i = asqrt6 / 12
  • Midsphere radius: r_k = a / sqrt8
  • Circumsphere radius: r_u = asqrt6 / 4

The tetrahedron volume calculator is useful for students studying 3D geometry, engineers designing space frame structures, chemists modeling molecular shapes, and anyone working with Platonic solids or polyhedral geometry.

Frequently Asked Questions

What is the formula for tetrahedron volume?

The formula for the volume of a regular tetrahedron (all edges equal) is V = a^3 / (6sqrt2), where a is the edge length. This can also be written as V = a^3 x sqrt2 / 12. For example, a tetrahedron with edge length 6 has volume = 216 / (6 x 1.414) = 25.46 cubic units.

What is a regular tetrahedron?

A regular tetrahedron is a Platonic solid with 4 equilateral triangle faces, 4 vertices, and 6 edges of equal length. It is the simplest of all polyhedra and the only one with exactly 4 faces. All dihedral angles are approximately 70.53 deg, and all face angles are 60 deg.

How is a tetrahedron different from a triangular pyramid?

A regular tetrahedron is a specific type of triangular pyramid where all four faces (including the base) are congruent equilateral triangles. A general triangular pyramid can have a base triangle with different side lengths and non-congruent side faces. The tetrahedron is the special case of a triangular pyramid with all edges equal.

What is the surface area of a regular tetrahedron?

The surface area of a regular tetrahedron is SA = sqrt3 x a^2, where a is the edge length. Each of the 4 equilateral triangle faces has area (sqrt3/4) x a^2. The total surface area is 4 x (sqrt3/4 x a^2) = sqrt3 x a^2. For a tetrahedron with edge 6, surface area = 1.732 x 36 = 62.35 square units.

What is the height of a regular tetrahedron?

The height of a regular tetrahedron is H = sqrt(2/3) x a, where a is the edge length. This can also be written as H = a x sqrt6 / 3. For a tetrahedron with edge 6, the height is 6 x 2.449 / 3 = 4.899 units.

What are the insphere, midsphere, and circumsphere of a tetrahedron?

A regular tetrahedron has three concentric spheres: the insphere (tangent to all faces) with radius r_i = asqrt6/12, the midsphere (tangent to all edges) with radius r_k = a/sqrt8, and the circumsphere (passing through all vertices) with radius r_u = asqrt6/4. For edge length 6, these radii are approximately 1.225, 2.121, and 3.674 units respectively.

What are real-world examples of tetrahedrons?

Real-world examples include tetrahedral kite structures, certain molecule shapes (methane CH4 is tetrahedral), dice with 4 sides (D4 used in RPGs), some tent designs, space frame structures, and the famous Tetra Pak carton shape. The tetrahedron is also the simplest 3D simplex used in mesh generation.

Is this tool free to use?

Yes, all calculators on Calculy are completely free to use with no registration required. You can also share your calculation results via URL.