Ellipsoid Calculator

Enter the three semi-axes (a, b, and c) of your ellipsoid to get the volume and approximate surface area in return. Works for any ellipsoid — including spheres, prolate spheroids (cigar-shaped), and oblate spheroids (lens-shaped). Results update as you type.

cm

Radius along the x-axis

cm

Radius along the y-axis

cm

Radius along the z-axis

Results

Volume

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Surface Area (approx.)

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Ellipsoid Type

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Semi-axis Lengths Comparison

Frequently Asked Questions

What is an ellipsoid?

An ellipsoid is a 3D surface shaped like a stretched or squashed sphere, where all cross-sections are ellipses. It is defined by three semi-axes a, b, and c along the x, y, and z axes respectively. A sphere is a special case where a = b = c.

How do I calculate the volume of an ellipsoid?

The volume of an ellipsoid is calculated using the formula V = (4/3) × π × a × b × c, where a, b, and c are the three semi-axes. For example, if a = 3 cm, b = 6 cm, and c = 8 cm, the volume is (4/3) × π × 3 × 6 × 8 ≈ 603.19 cm³.

How is the surface area of an ellipsoid calculated?

Unlike volume, the surface area of a general ellipsoid has no exact elementary formula. This calculator uses Thomsen's approximation: SA ≈ 4π × ((a^p × b^p + a^p × c^p + b^p × c^p) / 3)^(1/p), where p = 1.6075. This approximation is accurate to within about 1% for most ellipsoids.

What is the ellipsoid volume if the semi-axes are 3 cm, 6 cm, and 8 cm?

Using the formula V = (4/3) × π × a × b × c with a = 3, b = 6, c = 8: V = (4/3) × π × 3 × 6 × 8 ≈ 603.19 cm³.

Can an ellipsoid have a negative volume?

No. Volume is always a non-negative quantity. Since volume depends on the product of the three semi-axes (all of which must be positive lengths), the result is always a positive number.

Is the volume of an ellipsoid always less than that of a sphere?

Not necessarily. If an ellipsoid's semi-axes are larger than the radius of a given sphere, the ellipsoid can have a greater volume. However, among all ellipsoids with the same surface area, the sphere has the maximum volume.

What is the difference between a prolate and an oblate spheroid?

A spheroid is a special ellipsoid where two of the three axes are equal. A prolate spheroid (like a rugby ball) has one axis longer than the other two equal axes. An oblate spheroid (like the Earth) has one axis shorter than the other two equal axes.

What are real-life applications of ellipsoid volume calculation?

Ellipsoid volume calculations are widely used in medicine (estimating organ volumes from ultrasound measurements such as kidneys, liver, or tumors), engineering (tank and vessel design), astronomy (modeling planet shapes), and food science (estimating volumes of egg-shaped objects).

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