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.

クイックリファレンス

変換元変換先
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

使用例

計算式

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

よくある質問

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.