How it works
Ellipse area = π × semi-major axis × semi-minor axis. Enter half-axis lengths, not full diameters.
Input definitions
- Semi-major axis
- Enter the value in the labeled unit.
- Semi-minor axis
- Enter the value in the labeled unit.
A worked example
- Semi-major axis
- 5
- Semi-minor axis
- 3
Assumptions & limits
Uses the units and scope stated in the input labels. Results are rounded for display; verify the model is appropriate for your situation.
Sources & review
Maintained by AnsRio. Methods and examples use automated checks; this does not imply independent professional certification.
Method updated 2026-10-18. Content checked against the stated method and examples. Our verification approach.
Common questions
Should I enter the full width and height?
No. Divide each full axis by two before entering it. A circle is the special case where both semi-axes are equal.
How does Ellipse area work?
Ellipse area = π × semi-major axis × semi-minor axis. Enter half-axis lengths, not full diameters.
What should I check before using Ellipse area?
Uses the units and scope stated in the input labels. Results are rounded for display; verify the model is appropriate for your situation.