Math

Complex Number Calculator (Add, Multiply, Divide, Polar Form)

Enter two complex numbers a + bi and c + di and choose the operation.

Your numbers

Your results

Result
Result
—
Modulus |z|
—
Argument (degrees)
—
Polar form
—
Conjugate
—

Complex Number Calculator (Add, Multiply, Divide, Polar Form) by TheCalcTools

How the Complex Number Calculator (Add, Multiply, Divide, Polar Form) works

Add and subtract the real and imaginary parts separately. Multiply with i² = −1: (a + bi)(c + di) = (ac − bd) + (ad + bc)i.

To divide, multiply top and bottom by the conjugate of the divisor: (a + bi) ÷ (c + di) = [(ac + bd) + (bc − ad)i] ÷ (c² + d²). The modulus is √(x² + y²) and the argument is atan2(y, x).

The formula

(a + bi)(c + di) = (ac − bd) + (ad + bc)i(a + bi)/(c + di) = ((ac + bd) + (bc − ad)i) ÷ (c² + d²)

Worked example

Using the default values shown in the calculator:

a (real part of the first number)3
b (imaginary part of the first number)4
OperationDivide
c (real part of the second number)1
d (imaginary part of the second number)-2
  1. (3 + 4i) ÷ (1 − 2i) = -1 + 2i.
  2. |z| = 2.236068, argument 116.5651°.

Result:

Result-1 + 2i
Modulus |z|2.2361
Argument (degrees)116.5651
Polar form2.236068 ∠ 116.565051°
Conjugate-1 − 2i

Frequently asked questions

What is (3 + 4i) ÷ (1 − 2i)?

−1 + 2i.

Where are complex numbers used?

AC circuits, signal processing, control systems, quantum mechanics and fractals.

Sources and further reading

More in Math · All calculators

This calculator gives estimates for information only. Check important results independently before you rely on them. See our disclaimer.