c+CalcLantern

Ellipse

Find area and approximate perimeter from two semiaxes.

How this works

Area = πab. Perimeter uses Ramanujan’s second approximation. Inputs are semiaxes (half-widths), not full diameters.

Example

Using the example inputs, area (square units) is 47.1238898038.

A (units)
5
B (units)
3
Area (square units)
47.1238898038

Scope and assumptions

Uses your inputs only; results are rounded for display.

OpenStax mathematics

Related calculators

Trapezoid

Circle

Regular polygon

Area conversion

Percentage

BUILT FOR CLARITY

Useful tools. Honest answers.

An original collection of calculators for everyday estimates and learning.

Calculations run in your browser. This site does not send your inputs to a server or serve advertising. Optional analytics runs only after you allow it. Results are estimates within each tool’s stated scope, not professional advice.

Financial, health and building-related tools have specific limitations. Check important decisions with a qualified professional. No live currency rates, tax tables or current price feeds are connected.