Oblate Spheroid - Mass

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Equation / Last modified by KurtHeckman on 2019/04/14 01:37
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vCalc.Oblate Spheroid - Mass

The Mass or Weight of an Oblate Spheroid calculator computes the volume of an oblate spheroid based on the semi-major(b) and semi- minor (c) axis with the assumption that the spheroid is generated via rotation around the minor axis (see diagram).  Ellipsoid_OblateSpheroid.png

INSTRUCTIONS: Choose your length units for a and b (e.g. feet, meters, light-years), and enter the following:

  • (b) - semi-major axis, the distance from the oblate spheroid's center along the longest axis of the spheroid
  • (c) - semi-minor axis, the distance from the oblate spheroid's center along the shortest axis of the spheroid
  • (mD) - the mean density of the substance comprising the oblate spheroid.

Oblate Spheroid Mass / Weight: The mass (M) is returned in kilograms.  However, this can be automatically converted to other mass and weight units (e.g. tons, pounds) via the pull-down menu. 

Ellipsoid Calculator


The oblate spheroid is an ellipsoid that can be formed by rotating an ellipse about its minor axis.  The rotational axis thus formed will appear to be the oblate spheroid's polar axis. The oblate spheroid is fully described then by its semi-major and semi-minor axes.

One important shape in nature that is close to (though not exactly) an oblate spheroid is the Earth which has a semi-minor axis (c) which is the polar radius of 6,356 kilometers, and a semi-major axis (b) which is the equatorial radius of 6,378 kilometers.  Consideration: what force would make the equatorial radius larger than the polar radius?

Related Calculators

The following table contains links to calculators that compute the volume of other shapes:

                                          Other Volume Calculators
           Various ShapesPolygon Columns
Cube Triangular PrismTriangular
ConePolygon based PyramidPentagon
Cone FrustumPyramid FrustumHexagon
Slanted CylinderSphere CapOctagon
EllipsoidOblate SpheroidNonagon