Ellipse Area Calculator
Work out the area of an ellipse from its major and minor axis or radii with this free calculator, no downloads, right in your browser.
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Shape
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How to use this calculator
- Enter the two semi-axes.
- Press Calculate.
How it works
Area = π × semi-axis a × semi-axis b.
Worked example
a 2 m, b 3 m. ≈ 18.85 m².
Common mistakes
- Using the full axis lengths instead of the semi-axes — a and b are half of each axis.
- Treating it like a circle with one radius; an ellipse has two different semi-axes.
Frequently asked questions
How do I calculate the area of an ellipse?
Area = π × a × b, where a and b are the semi-major and semi-minor axes (half of each full axis).
What if both axes are equal?
Then a = b and the formula becomes πr² — an ellipse with equal axes is simply a circle.
What are the semi-axes?
Half of each full axis, measured from the centre to the edge: the semi-major (a) is the longer one and the semi-minor (b) the shorter.
Related tools
- Circle Area Calculator
- Equilateral Triangle Area Calculator
- Parallelogram Area Calculator
- Regular Hexagon Area Calculator
- Regular Pentagon Area Calculator
- Regular Polygon Area Calculator
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Cite this tool
Zerdly. (2026). Ellipse Area Calculator. Retrieved from https://www.zerdly.com/tools/ellipse-area-calculator/
Tip: Enter any known values to calculate the remaining results.
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