Torus Surface Area Calculator

Enter the tube radius and center radius of a torus (donut shape) to calculate its surface area instantly.

R r

Torus Surface Area Calculator

Our Torus Surface Area Calculator finds the outer surface area of a torus — the donut-shaped surface formed by revolving a circle around an axis outside of it — from its two radii.

What Is a Torus?

A torus is defined by two measurements: the center radius (R), the distance from the very center of the torus to the center of the tube, and the tube radius (r), the radius of the circular cross-section (the "tube") that was revolved around to form the shape.

Torus Surface Area Formula

Surface Area = 4 × π² × R × r

Where R is the center radius and r is the tube radius.

Example Calculation

R = 8, r = 3

Surface Area = 4 × π² × 8 × 3 ≈ 947.48

✓ Surface Area ≈ 947.48

Features of Our Torus Surface Area Calculator

✅ Labeled diagram for quick visual reference
✅ Instant, accurate results
✅ Simple, focused interface
✅ Free to use, no sign-up required

Who Can Use This Calculator?

Students & Teachers – For geometry and solid-shape homework
Engineers & Designers – For gaskets, seals, and ring-shaped parts
3D Artists & Modelers – For surfacing and material estimates
Bakers & Crafters – For donut and ring-shaped project math

👉 Try our Torus Surface Area Calculator to find any torus's surface area in seconds.