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Center of Ellipse Calculator.

Find the center of an axis-aligned ellipse from its extrema.

On-device calculationNo signup
01

Set your values

Results update as you type.

Center x: 1

Center x

0.000000
Center y: 3

Center y

0.000000

Results update automatically as you type.

Use Cases

Graphing and geometry problems

Quickly determine the center of an ellipse when you know its extreme points, useful for plotting or solving geometry exercises.

Example: Given left x=1, right x=5, bottom y=2, top y=6, the center is (3,4).

Engineering and design

Find the center of an elliptical component or feature from its bounding box measurements for manufacturing or CAD alignment.

Example: If an elliptical hole spans x=10 to x=30 and y=5 to y=15, its center is (20,10).

Frequently Asked Questions

How do I find the center of an ellipse using this calculator?
Enter the x-coordinates of the left and right extrema, and the y-coordinates of the bottom and top extrema. The calculator computes the center as the midpoint of the horizontal and vertical extents.
What does 'axis-aligned' mean for an ellipse?
An axis-aligned ellipse has its major and minor axes parallel to the x and y axes. Its extrema are simply the leftmost, rightmost, bottommost, and topmost points, which you input here.
Can I use this calculator for a circle?
Yes, a circle is a special case of an ellipse. Enter the left and right x values (diameter endpoints) and the bottom and top y values (diameter endpoints) to get the circle's center.

Tips & Common Mistakes

Tips

  • Ensure the left x is less than the right x, and the bottom y is less than the top y, for a valid ellipse.
  • The center is simply the average of the left and right x values, and the average of the bottom and top y values.
  • You can use negative coordinates; the calculator handles them correctly.
  • Double-check your input values to avoid sign errors, especially when extrema are negative.

Common Mistakes to Avoid

  • Entering the x and y values in the wrong fields (e.g., swapping left and right).
  • Using the coordinates of the foci or vertices instead of the extrema (leftmost, rightmost, bottommost, topmost points).
  • Assuming the center is the midpoint of only one pair of extrema; you need both horizontal and vertical pairs.

Last updated: August 13, 2026