Complex Number Calculator — Free Online Tool

Add/subtract/multiply/divide complex numbers.. Complex Number Calculator is a free online tool from the ToolsRift Math Calculators collection. It runs entirely in your browser — nothing to install, no signup, and your data never leaves your device.

Loading Complex Number Calculator

How to use Complex Number Calculator

Enter the real and imaginary parts of two complex numbers, choose an operation, and the result is shown in a+bi form.

Frequently asked questions

How are complex numbers written?

In the form a + bi, where a is the real part, b the imaginary part, and i is √(−1).

How is complex multiplication done?

(a+bi)(c+di) = (ac−bd) + (ad+bc)i, using the rule that i² = −1.

How does complex division work?

Multiply the numerator and denominator by the conjugate of the denominator to remove i from the bottom.

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