Major Axis of an Ellipse Calculator

What is the Major Axis?

The major axis of an ellipse is its longest diameter, passing through the center of the ellipse. It represents the maximum distance across the ellipse.

How to Use This Calculator

1. Enter the length of the semi-major axis (a) - this is half of the major axis
2. Enter the length of the semi-minor axis (b) - this is half of the minor axis
3. Click the "Calculate" button to compute the major axis
4. The result will be displayed as 2 × semi-major axis

Geometric Significance

The major axis determines the overall size and shape of the ellipse. In an ellipse, the major axis is always aligned with the two foci of the ellipse. The relationship between the semi-major axis (a), semi-minor axis (b), and distance to each focus (c) follows the equation: c² = a² - b²

Example

If you have an ellipse with a semi-major axis of 5 units and a semi-minor axis of 3 units, the major axis would be 2 × 5 = 10 units long.