Circle from Diameter Endpoints

Enter x₁.
Enter y₁.
Enter x₂.
Enter y₂.
Math

Circle from Diameter Endpoints: calculate results from explicit inputs, with a formula and worked example.

Formula

center = midpoint of endpoints; radius = endpoint distance/2

Example Calculation

Example inputs
  • x₁: 0
  • y₁: 0
  • x₂: 6
  • y₂: 8

Diameter endpoints (0,0) and (6,8) give center (3,4), radius 5.

Frequently asked questions

How do I use this calculator?

Enter x₁, y₁, x₂, y₂. The result updates automatically. Use Reset to restore the example values.

What method does it use?

center = midpoint of endpoints; radius = endpoint distance/2. Euclidean geometry. Use one consistent length unit; areas and volumes use its square and cube. Degenerate shapes are rejected. Very thin shapes may lose floating-point precision.

Why might a rounded result differ?

The calculation keeps full numeric precision internally, then rounds the displayed result. Rounding intermediate steps by hand can produce a slightly different answer.

Are my inputs saved online?

No. This calculator processes your inputs in your browser. A recently used list stores only calculator names on this device, not your entered values.

Check the assumptions and units before using this result. Read about calculation methods.