Complex Number Calculator
Add, subtract, multiply or divide two complex numbers.
Perform the four basic operations on complex numbers of the form a + bi.
The math behind it
Multiplication: (a+bi)(c+di) = (ac − bd) + (ad + bc)i. Division multiplies by the conjugate of the denominator: result = (a+bi)(c−di) ÷ (c² + d²).
Worked example
(3 + 2i)(1 − 4i) = (3 + 8) + (−12 + 2)i = 11 − 10i.
FAQ
What is i?
The imaginary unit, defined by i² = −1.