Ellipse Calculator
Calculate area and approximate circumference from semi-major and semi-minor axes.
Formula
A = πab, C ≈ π(3(a+b)−√((3a+b)(a+3b)))
Area is π times semi-major times semi-minor axis. Circumference uses the Ramanujan approximation.
Examples
a=6, b=4
a=10, b=3
Circle (a=b=5)
Frequently Asked Questions
What is the area of an ellipse?
A = π × a × b, where a and b are the semi-major and semi-minor axes.
How is the circumference of an ellipse calculated?
There is no simple closed-form. The Ramanujan approximation C ≈ π(3(a+b)−√((3a+b)(a+3b))) is widely used.
About this Calculator
Calculate area and approximate circumference from semi-major and semi-minor axes. All calculations are performed in your browser for instant results. Formulas are mathematically exact using JavaScript's built-in Math functions.