Equation of a Circle Calculator
Standard Form
(x - h)² + (y - k)² = r²
General Form
x² + y² + Dx + Ey + F = 0
Center
(0, 0)
Radius
5
units
Diameter
10
units
Area
78.54
square units
Equations
(x - 0)² + (y - 0)² = 5²
x² + y² + 0x + 0y - 25 = 0
About Circle Equations
The equation of a circle can be expressed in two forms:
- Standard Form: (x - h)² + (y - k)² = r²
- h, k are the coordinates of the center
- r is the radius
- General Form: x² + y² + Dx + Ey + F = 0
- Center: (-D/2, -E/2)
- Radius: √(D²/4 + E²/4 - F)