Complex Number Calculator

Our Complex Number Calculator handles every standard complex arithmetic operation in one place. Enter numbers in rectangular form (a + bi) or polar form (r∠θ), then choose from addition, subtraction, multiplication, division, modulus, argument, conjugate, polar conversion, exponentiation using De Moivre's theorem, nth roots, and complex exponential e^z. Every operation shows detailed step-by-step working so you can follow the method, verify your work, or learn the underlying mathematics.

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Z₁ = 3 + 4i | |Z₁| = 5 | arg = 53.13°

Z₂ = 1 − 2i

Quick Examples:

Result (Rectangular)

Polar Form

Modulus |Z|

Argument θ

functions Key Formulas

Modulus
|z| = √(a² + b²)
Argument
θ = atan2(b, a)
Conjugate
z* = a − bi
Multiply
(ac−bd) + (ad+bc)i
Divide
×conj(z₂) / |z₂|²
De Moivre (Power)
z^n = rⁿ∠nθ
Euler's Formula
e^(a+bi) = eᵃ(cos b + i sin b)

scatter_plot Powers of i

i⁰ = 1
= i
= −1
= −i
i⁴ = 1 (repeats)

iⁿ cycles with period 4: use n mod 4

lightbulb Quick Tips

  • e^(iπ) + 1 = 0 (Euler's identity)
  • Polar multiply: add angles, multiply moduli
  • n-th roots are equally spaced by 360°/n
  • z + z* = 2a (always real)
  • z × z* = a² + b² = |z|²

How to Use This Calculator

1

Enter Z₁

Enter the real and imaginary parts of the first complex number Z₁ = a + bi

2

Enter Z₂ (if needed)

For binary operations (add, subtract, multiply, divide), also enter Z₂ = c + di

3

Choose Operation

Select from 11 operations: arithmetic, modulus, argument, conjugate, polar form, power, roots, or e^z

4

View Result & Steps

See the result in both rectangular (a+bi) and polar (r∠θ) forms with step-by-step working

The Formula

A complex number z = a + bi has real part a and imaginary part b. The modulus is |z| = √(a²+b²). The argument θ = atan2(b, a). Multiplication is easiest in polar form: |z₁||z₂|∠(θ₁+θ₂). Division: (|z₁|/|z₂|)∠(θ₁−θ₂). Powers by De Moivre: z^n = rⁿ(cos nθ + i·sin nθ).

z = a + bi, |z| = √(a²+b²), z^n = rⁿ(cos nθ + i sin nθ)

lightbulb Variables Explained

  • a Real part of complex number
  • b Imaginary part of complex number
  • |z| Modulus (absolute value) — distance from origin
  • θ Argument — angle from positive real axis
  • z* Complex conjugate — z* = a − bi
  • r∠θ Polar form — r is modulus, θ is argument

tips_and_updates Pro Tips

1

Remember: i² = −1. This is the key identity for complex multiplication

2

Modulus and argument: |z| = √(a²+b²), θ = atan2(b, a)

3

Conjugate of (a+bi) is (a−bi). Multiplying z·z* = |z|² (always real)

4

For powers and roots, De Moivre's theorem is far easier than expanding

5

Polar multiplication: multiply moduli, add arguments

6

The n-th roots of z are equally spaced around a circle of radius ⁿ√|z|

Perform Complex Number Arithmetic with Step-by-Step Solutions

Complex numbers extend the real number system by introducing the imaginary unit i, where i-squared equals negative one. Far from being a purely abstract concept, complex numbers are essential tools in electrical engineering for analyzing AC circuits using phasor notation, in signal processing for representing frequency components via the Fourier transform, in control systems for stability analysis, and in quantum mechanics for describing wave functions. A complex number z = a + bi has a real part a and imaginary part b, and can equivalently be expressed in polar form as r times e-to-the-i-theta, where r is the magnitude and theta is the argument. Converting between rectangular and polar forms, computing products and quotients, finding powers and roots — these operations follow specific rules that are straightforward but tedious to perform by hand, especially when precision matters. This complex number calculator handles all standard operations including addition, subtraction, multiplication, division, powers, nth roots, conjugates, and magnitude calculations, showing detailed step-by-step solutions for each operation.

What is a Complex Number Calculator?

A complex number calculator performs arithmetic and geometric operations on numbers of the form a + bi, where i is the imaginary unit (i² = −1). Our calculator supports all standard operations: addition, subtraction, multiplication, division, modulus, argument, conjugate, polar form conversion, De Moivre powers, nth roots, and complex exponential.

Rectangular vs Polar Form

Complex numbers can be expressed in rectangular form (a + bi) or polar form (r∠θ). The modulus r = √(a²+b²) is the distance from the origin, and the argument θ = atan2(b,a) is the angle. Polar form makes multiplication, division, and powers much simpler: multiply moduli and add arguments.

Frequently Asked Questions

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All formulas verified against official standards.