ClarityKitFind a tool
Geometry

Ellipse Perimeter Calculator

Estimate an ellipse boundary with Ramanujan’s approximation.

Use consistent dimensionsArea and volume units explained below

Shape dimensions

Runs on your device

GEOMETRIC RESULT

Your result

Let’s calculate.

Use the Calculate button to see your result.

Review the method below for assumptions and conventions.

How to use this tool

  1. Enter first semiaxis, second semiaxis.
  2. Select Calculate to view the result.
  3. Check the method and assumptions below before using the result.

The method, explained

h = ((a − b)/(a + b))². Perimeter ≈ π(a + b)[1 + 3h/(10 + √(4 − 3h))].

A WORKED EXAMPLE

Using first semiaxis = 5 m, second semiaxis = 3 m, the result is 25.5269989 m. Change these example inputs to match your task; use the method above to check each step.

What to keep in mind

Approximation, not an exact elliptic-integral evaluation. Use the indicated units consistently. Ideal shapes are assumed; dimensions must describe the same object. Display rounding does not increase measurement precision.

Common questions

Which inputs does this calculation need?

Estimate an ellipse boundary with Ramanujan’s approximation. Enter first semiaxis in m, second semiaxis in m. The filled example is editable and is not a saved personal record.

How should I interpret the result?

Approximation, not an exact elliptic-integral evaluation. Use the indicated units consistently. Ideal shapes are assumed; dimensions must describe the same object. Display rounding does not increase measurement precision.

Methodology maintained by ClarityKit. How these tools are built and checked.