The Ellipsoid Calculator provides equations and data to compute the volume, surface area , mass and weight of ellipsoids including the specials cases of an ellipsoid: the oblate spheroid and the sphere. 
- Ellipsoid - Volume computes the volume of an ellipsoid based on the length of the three semi-axes (a, b, c)
- Ellipsoid - Surface Area computes the surface area of an ellipsoid based on the length of the three semi-axes (a, b, c)
- Ellipsoid - Mass or Weight computes the mass or weight of an ellipsoid based on the length of the three semi-axes (a, b, c) and the mean density.
- Oblate Spheroid - Volume computes the volume of an Oblate Spheroid based on the length of the two semi-axes (b, c)
- Oblate Spheroid- Surface Area computes the surface area of an Oblate Spheroid based on the length of the two semi-axes (b, c)
- Oblate Spheroid- Mass or Weight computes the mass or weight of an Oblate Spheroid based on the length of the two semi-axes (b, c) and the mean density.
- Sphere - Volume computes the volume of a sphere based on the length of the radius (a)
- Sphere - Surface Area computes the surface area of a sphere based on the length of the radius (a)
- Sphere - Mass or Weight computes the mass or weight of a sphere based on the length of the radius (a) and the mean density.
- Common Mean Density provides a lookup capability to find the mean density of hundreds of materials (woods, metals, liquids, chemicals, food items, soils, and more)
The Math / Science
An ellipsoid has three axes if different lengths. However each axis has the cross-section of an ellipse. When the two of the axes have the same length, the formulas are simplified to create an oblate spheroid. When all three axes are the same length, the result is a perfect sphere.