Circle General to Standard Form

Enter d in x²+y²+dx+ey+f=0.
Enter e.
Enter f.
Math

Circle General to Standard Form: calculate results from explicit inputs, with a formula and worked example.

Formula

h = −D/2; k = −E/2; r² = (D²+E²)/4−F

Example Calculation

Example inputs
  • D in x²+y²+Dx+Ey+F=0: -6
  • E: -8
  • F: 0

x²+y²−6x−8y=0 becomes (x−3)²+(y−4)²=25.

Frequently asked questions

How do I use this calculator?

Enter d in x²+y²+dx+ey+f=0, e, f. The result updates automatically. Use Reset to restore the example values.

What method does it use?

h = −D/2; k = −E/2; r² = (D²+E²)/4−F. 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.