When to use this calculator
Calculate the enclosed area of an ellipse using its two semi-axes. Semi-axes are half of the full width and height.
Explore the circle & ellipse calculators for other questions in this topic. For a related calculation, use the Ellipse Perimeter Calculator: Estimate the circumference of an ellipse from its semi-axes.
PUTTING IT INTO PRACTICE
Ellipse Area: a worked example
The values below are an illustrative example, not a recommendation. Replace them with measurements or assumptions that match your question.
| Input | Example value |
|---|---|
| Semi-major axis | 6 |
| Semi-minor axis | 4 |
| Result | 75.398224 square units |
- Check the input labels and enter the example values above.
- Apply the relationship: Area = πab.
- The result is 75.398224 square units, rounded for display.
How to interpret your result
Semi-axes are half of the full width and height.
Distinguish radius from diameter before entering measurements. Arc length follows the curve, while chord length runs straight between endpoints. Ring-shaped areas subtract the inner circle from the outer one.
Frequently asked questions
How is chord length different from arc length?
A chord is a straight line between two points on the circle. An arc follows the circular boundary between those points.
How do I use the ellipse area calculator?
Enter semi-major axis, semi-minor axis. The result updates automatically. Use the units shown beside each input; the example values illustrate the method.
Which formula does this calculator use?
Area = πab.
What should I check before using the result?
Semi-axes are half of the full width and height.
How are results rounded?
Scalar numbers display up to six decimal places, with scientific notation for very large or small values. Text, fraction, date and schedule outputs use the format described on the tool. Intermediate calculations use JavaScript floating-point arithmetic. Keep sensible precision for your measurements.
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