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Last updated: July 31, 2026

General Form of a Circle Calculator

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Formula

D = -2h, E = -2k, F = h² + k² - r²

Where:

  • h=Center h
  • k=Center k
  • r=Radius r

Worked Examples

Shifted circle

Center (3,-2), radius 5.

  1. 1D=-2(3)=-6
  2. 2E=-2(-2)=4
  3. 3F=3²+(-2)²-5²= -12
Final Answer: D=-6, E=4, F=-12, equation=x^2 + y^2 - 6x + 4y - 12 = 0

Origin-centered circle

Center (0,0), radius 7.

  1. 1D=0 and E=0
  2. 2F=0+0-49=-49
  3. 3Write compact equation
Final Answer: D=0, E=0, F=-49, equation=x^2 + y^2 - 49 = 0

Decimal parameters

Center (1.5,2.5), radius 4.

  1. 1D=-3 and E=-5
  2. 2F=1.5²+2.5²-16=-7.5
  3. 3Assemble equation
Final Answer: D=-3, E=-5, F=-7.5

Introduction

This converter maps geometric circle parameters to polynomial coefficients used in algebraic and analytic geometry.

Formula and Method

General Form of a Circle Calculator applies D = -2h, E = -2k, F = h² + k² - r² and returns deterministic outputs from validated inputs.

  • Validate each required input

  • Apply the stated formula

  • Round numeric outputs where needed

  • Return safe defaults when validation fails

Input Fields

Use these keys exactly as defined in calculation.ts.

  1. 1

    h: Center h

  2. 2

    k: Center k

  3. 3

    r: Radius r

Output Fields

These values map directly to calculation.ts return keys.

  1. 1

    D: Linear coefficient of x term

  2. 2

    E: Linear coefficient of y term

  3. 3

    F: Constant term in general form

  4. 4

    equation: Formatted general-form equation string

Validation Rules

h and k must be finite and radius r must be a positive finite value.

  • Finite numeric values are required

  • Domain restrictions are enforced before solving

  • Invalid input returns default-safe outputs

  • Check examples to confirm expected behavior

How to Use This Calculator

Enter inputs, run the calculation, and read the primary output first.

  • Enter all required values

  • Click calculate

  • Review primary output first

  • Use supporting outputs for interpretation

Practical Uses

This calculator is useful for study, verification, and fast applied math checks.

  • Conic-equation conversion

  • Geometry homework

  • Graphing software input

  • Algebraic manipulation checks

FAQs

What does the General Form of a Circle Calculator compute?

It computes D Coefficient and supporting outputs from your inputs.

Which inputs are required?

Required inputs are: Center h, Center k, Radius r.

How are invalid inputs handled?

When validation fails, the calculator returns safe default values and does not attempt invalid math.

Are results rounded?

Yes. Numeric outputs are rounded inside calculation.ts (typically to 6 decimal places).

Can I use negative or decimal values?

Finite values are accepted with radius strictly greater than zero.

How should I verify my answer?

Use the worked examples and compare each output key with your manual steps.