Math formulas

Solid geometry formulas

Calculate volumes, surface areas, and dimensions of common three-dimensional solids.

Formulas and calculators

Cube and cuboid volume and surface area

Calculate volume, total surface area, or a missing edge of a cube or rectangular cuboid.

Cuboid: V = abc, S = 2(ab + ac + bc); cube: V = a³, S = 6a²

Calculated quantities

V - volume · S - total surface area · a - cube edge · a - cuboid length · b - cuboid width · c - cuboid height

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How to choose the right formula

Cube and cuboid volume and surface area

Cuboid: V = abc, S = 2(ab + ac + bc); cube: V = a³, S = 6a²
When to use it
Cuboid volume is the product of its three edges, and its surface area is the sum of the six rectangular faces. A cube is the special case with equal edges.
Calculated quantities
V - volume (m³) · S - total surface area (m²) · a - cube edge (m) · a - cuboid length (m) · b - cuboid width (m) · c - cuboid height (m)
Worked example: Volume of a cube
A cube has an edge length of 4 cm. Calculate its volume.
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What to check before calculating

Assumptions and conditions

  • The cuboid has rectangular faces and three mutually perpendicular edge directions.
  • All cube edges are equal; cuboid edges may differ.
  • Every edge length must be positive.
  • Volume uses cubic units, surface area uses squared units, and edges use linear units.

Common mistakes

  • Using squared units for volume or cubic units for surface area.
  • Forgetting that each cuboid face has an opposite congruent face.
  • Using the cube formulas when the three cuboid edges are not equal.
  • Adding edges instead of multiplying them when calculating volume.