Complex Number Polar Form Calculator

Convert a complex number between rectangular (a + bi) and polar (r∠θ) form.

  • Free to use
  • Accurate results
  • No registration required
  • Works on all devices
Choose a direction and enter either the real/imaginary parts or the magnitude/angle to convert a complex number's form.
Convert

Your result

5

Magnitude (r)

Angle (θ, degrees)53.13
Real part3
Imaginary part4

AI explanation

Formula

To polar: r = √(a² + b²), θ = arctan(b ÷ a). To rectangular: a = r·cos(θ), b = r·sin(θ)

Worked example

3+4i to polar form

Worked example: 3+4i to polar form
FieldValue
Convertto-polar
Real part3
Imaginary part4
Magnitude (r)5
Angle (θ, degrees)53.13010235
Real part3
Imaginary part4

Assumptions

  • The angle is measured counterclockwise from the positive real axis, in degrees.

Frequently asked questions

What is polar form?

A way to represent a complex number by its distance from the origin (magnitude, r) and the angle from the positive real axis (θ), instead of separate real and imaginary parts.

How do I convert rectangular to polar form?

Magnitude r = √(a² + b²) (the Pythagorean theorem); angle θ = arctan(b ÷ a), adjusted for the correct quadrant.

Why do the input fields change based on direction?

Converting to polar form needs the real and imaginary parts; converting back to rectangular form needs the magnitude and angle instead — so only the relevant fields are shown.

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