Use this geometry calculation when the shape, dimensions, coordinate system, and units match the stated ideal Euclidean model.

Semi-major axis

Required number input.

Semi-minor axis

Required number input.

Compute the area of an ellipse from its semi-major and semi-minor axes. The tool evaluates the supplied inputs together and returns the named outputs below; it does not infer omitted operating conditions or change the units shown.^[1]

Area

The resulting area returned as a number.

• The result assumes exact idealized geometry. Measurement uncertainty, rounded inputs, nonplanarity, self-intersection, thickness, curved coordinate systems, and ambiguous dimension definitions are not automatically represented.
• Use finite inputs in the displayed units and preserve more precision than the final presentation requires. Independently verify safety-critical, financial, compliance, or production decisions.

Sketch and label the dimensions, verify unit consistency, and use coordinate or CAD methods for irregular measured shapes.

• Ellipsoid Volume Calculator

  Calculate the volume of an ellipsoid from its three semi-axes as (4/3)π·a·b·c.

• Annulus Area Calculator

  Calculate the area of an annulus from its outer and inner radii as π(R²−r²).

• Circle Sector Area Calculator

  Compute the area of a circular sector from its central angle and radius.