Torus (Donut) Volume Calculator
Calculate the volume and surface area of a torus (donut shape) from its major radius and minor (tube) radius.
Torus (Donut) Volume & Surface Area Mathematics
Torus calculator computes the volume and surface area of a donut-shaped solid from its major radius and minor (tube) radius.
A torus is generated by revolving a circle of radius r (the tube) around an axis at distance R (the major radius) from the circle's center. Its volume and surface area formulas come from Pappus's centroid theorems for solids of revolution.
- 1Enter the major radius (R, center to tube middle) and minor radius (r, tube thickness).
- 2View the torus's volume and surface area.
A donut-shaped ring has a major radius of 10 units and a tube (minor) radius of 3 units.
Frequently Asked Questions (FAQ)
The major radius (R) is the distance from the center of the whole torus to the center of the tube; the minor radius (r) is the radius of the tube itself — think of R as the donut's overall size and r as its thickness.
Donuts, inner tubes, O-ring seals, and bagels are all approximately torus-shaped — the formulas here apply anywhere a tube is bent into a complete loop.
Top Similar Tools (Math)
Explore more tools in Math (83+ more calculators available)
Browse our complete directory with category filters, formulas, and verified engines.