OhMyCalc

Ellipse Area Calculator

Calculate the area and approximate perimeter of an ellipse by entering the semi-major and semi-minor axes. Uses Ramanujan's approximation for perimeter.

How to Use the Ellipse Area Calculator

  1. Enter the required dimensions (length, width, radius, height, etc.).
  2. The area, volume, or other geometric value is computed instantly.
  3. Review the result along with the formula used.
  4. Adjust dimensions to compare different scenarios.

Quick Reference

FromTo
a=2, b=318.85
a=3, b=547.12
a=4, b=675.40
a=5, b=8125.66
a=5, b=10157.08
a=10, b=15471.24

Use Cases

Formula

Formula: S = π × a × b. Perimeter ≈ π(3(a+b) − √((3a+b)(a+3b))) (Ramanujan approximation).

Frequently Asked Questions

How do you calculate the area of an ellipse?
Multiply π by the semi-major axis (a) and semi-minor axis (b): S = π × a × b.
How is the perimeter of an ellipse calculated?
There is no exact closed-form formula. Ramanujan's approximation P ≈ π(3(a+b) − √((3a+b)(a+3b))) is very accurate.
What are the semi-major and semi-minor axes?
The semi-major axis (a) is half the longest diameter, and the semi-minor axis (b) is half the shortest diameter of the ellipse.
Is a circle a special case of an ellipse?
Yes. When a = b = r, the ellipse becomes a circle with area πr² and perimeter 2πr.