When to use this calculator
Find the outside surface area of a ring-shaped torus. Requires a ring torus with tube radius below major radius.
Explore the volume & surface area calculators for other questions in this topic. For a related calculation, use the Torus Volume Calculator: Calculate the volume of a ring-shaped torus.
PUTTING IT INTO PRACTICE
Torus Surface Area: a worked example
The values below are an illustrative example, not a recommendation. Replace them with measurements or assumptions that match your question.
| Input | Example value |
|---|---|
| Major radius | 5 |
| Tube radius | 2 |
| Result | 394.784176 square units |
- Check the input labels and enter the example values above.
- Apply the relationship: Surface area = 4π² × major radius × tube radius.
- The result is 394.784176 square units, rounded for display.
How to interpret your result
Requires a ring torus with tube radius below major radius.
Volume and surface area have different units and answer different questions. Use internal dimensions for capacity. A closed-solid surface area includes bases and lids unless the calculator explicitly describes an open shape.
Frequently asked questions
Should I use internal or outside measurements?
Use internal measurements for capacity and outside measurements for covering the exterior. Match the formula to the part being measured.
When is the torus surface area calculator useful?
Find the outside surface area of a ring-shaped torus. Requires a ring torus with tube radius below major radius.
How do I use the torus surface area calculator?
Enter major radius, tube radius. The result updates automatically. Use the units shown beside each input; the example values illustrate the method.
Which formula does this calculator use?
Surface area = 4π² × major radius × tube radius.
What should I check before using the result?
Requires a ring torus with tube radius below major radius.
How are results rounded?
Scalar numbers display up to six decimal places, with scientific notation for very large or small values. Text, fraction, date and schedule outputs use the format described on the tool. Intermediate calculations use JavaScript floating-point arithmetic. Keep sensible precision for your measurements.
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