What you provide
What you provide
- First semi-axis: Center-to-edge distance along one ellipse axis.
- Second semi-axis: Center-to-edge distance along the perpendicular axis.
GEOMETRY / OVAL
Ellipse Calculator
Calculate exact ellipse area, approximate perimeter, eccentricity, and full major-axis length from two semi-axes.
- 01 Calculated in this tab
- 02 Values stay in this browser tab
- 03 Use boundary
Use boundary
Calculation path
The larger input is treated as semi-major; area is exact and Ramanujan’s approximation supplies perimeter.
Calculation path
Area = pi ab; perimeter approximately pi(a+b)(1 + 3h/(10 + sqrt(4 - 3h))).
What you receive
What you receive
- Exact ellipse area
- Approximate perimeter
- Eccentricity and major-axis length
Use boundary
Choose the maximum decimal places shown. This does not increase source accuracy.
Perimeter is a high-quality approximation and both inputs must be semi-axis lengths, not full diameters.
This is an educational planning result, not a structural, electrical, thermal, solar, battery, generator, or safety design. Confirm specifications, units, codes, and professional requirements before acting.