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Torus Volume Calculator

Kaushik RabadiyaCreated by Kaushik RabadiyaLast updated: September 24, 2026

Torus volume instantly calculates results using inner radius, outer radius, r1. Use the calculator above for instant answers in your browser.

Welcome to the Torus Volume Calculator, a specialized tool designed to help students, engineers, and designers determine the exact three-dimensional capacity of donut-shaped geometric objects. Whether you are modeling mechanical seals, designing architectural elements, or studying advanced calculus, this calculator eliminates manual arithmetic errors and delivers instant, precise results based on your choice of radius parameters.

How the Torus Volume Formula Works

A torus is a surface of revolution generated by revolving a circle in a three-dimensional space about an axis that is coplanar with the circle. To calculate its volume, mathematicians typically rely on Pappus's centroid theorem or multi-variable integration. Using the tube radius (r) and the distance from the center of the tube to the center of the torus, known as the major or revolution radius (R), the primary formula is expressed as V = 2 * pi^2 * R * r^2. Alternatively, if your measurements are based on the inner radius (r1) and outer radius (r2) of the ring structure, the volume can be determined through the derived equation V = 0.25 * pi^2 * (r2 + r1) * (r2 - r1)^2.

Worked Calculation Example

Let us walk through a practical scenario where you need to find the volume of a hollow ring-shaped gasket. Suppose your inner radius (r1) measures 3 centimeters, and your outer radius (r2) measures 7 centimeters. First, compute the tube radius by finding the difference between the outer and inner radii and dividing by two: r = (7 - 3) / 2 = 2 cm. Next, find the revolution radius by taking the average of the inner and outer radii: R = (7 + 3) / 2 = 5 cm. Finally, apply the standard volume equation: V = 2 * pi^2 * R * r^2. Substituting our values gives V = 2 * (3.14159)^2 * 5 * (2)^2 = 197.39 cubic centimeters. Thus, the total material volume of the torus is approximately 197.39 cm³.

Best Practices and Practical Tips

Always ensure your input units are consistent before running calculations; mixing millimeters and centimeters will lead to severe errors in volume output. When dealing with physical objects like O-rings or inflatable tubes, remember that inner and outer radii measurements must account for material thickness precisely at the widest cross-section. Double-check whether your specific drafting software defines the ring using center-to-tube radius dimensions or total inner-outer boundaries to feed the correct variables into your equations.

FAQs

What is a torus?

A torus is a geometric surface shaped like a doughnut or a ring. It is formed by rotating a closed two-dimensional circle around a fixed axis located outside the circle but on the same plane, meaning it creates a continuous hollow loop with a circular cross-section.

How is a torus formed?

A torus is created through a revolution process in three-dimensional space. Imagine taking a flat circular disc and sweeping it in a complete 360-degree circle around a central axis without letting the path intersect the circle itself. The resulting solid sweep is a torus.

What is the equation of a torus?

Algebraically, a torus symmetrical to the z-axis is defined implicitly in Cartesian coordinates by the equation (R - sqrt(x^2 + y^2))^2 + z^2 = r^2, where R represents the distance from the center of the tube to the axis of revolution, and r represents the radius of the tube itself.

How to calculate volume of a torus?

To find the volume of a torus, you multiply 2 by the square of pi, then multiply that product by the major radius (distance from the central axis to the tube center) and the square of the minor radius (the radius of the tube cross-section). This calculates the total space enclosed within the ring boundary.

Formula verified against Mathematical standards (ISO 80000-2) — all calculations use deterministic, standards-based formulas.

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