Enter the major radius R and minor radius r, choose the precision, and click "Calculate".
Calculator
A torus is a 3D shape that looks like a donut or an inner tube. It is formed by revolving a circle around an axis in its plane that does not intersect the circle.
Torus parameters:
- R — major radius: distance from the center of the torus to the center of the tube;
- r — minor radius: radius of the tube itself.
Required condition: R > r > 0. If r ≥ R, the shape ceases to be a torus as the tube intersects itself.
Surface area formula
where R is the major radius and r is the minor radius of the torus.
Example
Let R = 5 cm, r = 2 cm:
SA = 4 × π² × 5 × 2 ≈ 394.8 cm²
Applications:
Torus surface area calculations are used in engineering (pipelines, gaskets), industrial design, and 3D modeling — whenever you need to estimate material or coating for toroidal parts.