Semi Major Axis of an Ellipse Calculator

Posted by Dinesh on

Online geometry calculator to calculate semi major axis of an ellipse from the eccentricity, semi-minor values.

What is Semi Major Axis?

The semi major axis is one half of the major axis, and thus runs from the centre, through a focus, and to the perimeter. Essentially, it is the radius of an orbit at the orbit's two most distant points. For the special case of a circle, the semi-major axis is the radius. One can think of the semi-major axis as an ellipse's long radius.

Ellipse Semi Major Axis Calculation

Formula:

a = b ÷ √1 - ϵ²

Where,
b = semi-minor axis
ϵ = eccentricity
a = semi-major axis