Complex Number Calculator
Perform calculations with complex numbers online.
- A free tool that saves time and avoids manual errors.
- Free, no sign-up, works on any device.
Figures are estimates from this calculator’s standard formula — adjust the inputs in the tool below for your exact number.
How the Complex Number Calculator Works
Complex numbers consist of a real part (a) and an imaginary part (bi), where i is the square root of -1. They are essential in electrical engineering, signal processing, quantum physics, and advanced mathematics.
- 1
Enter First Number
Input the real and imaginary parts of the first complex number (a + bi)
- 2
Enter Second Number
Input the second complex number if needed for binary operations
- 3
Select Operation
Choose add, subtract, multiply, divide, magnitude, phase, or conjugate
- 4
View Result
The result displays as a complex number with magnitude and phase
Use Cases
Electrical Engineering
Analyze AC circuits, calculate impedance and phase angles
Signal Processing
Perform Fourier analysis and signal transformations
Quantum Physics
Describe particle states and wave functions
Computer Graphics
Represent rotations and transformations in 2D space
Tips
- 1
Use polar form (r at angle theta) for easier multiplication and division
- 2
Magnitude |z| = sqrt(a^2 + b^2) gives the distance from origin
- 3
The conjugate z* = a - bi is used to simplify division
- 4
Phase angle theta = arctan(b/a) indicates direction in the complex plane
Common Mistakes
Forgetting that i^2 = -1 - when multiplying, (bi)(di) = -bd
Dividing directly by a complex number - multiply by the conjugate instead
Confusing Cartesian (a + bi) and polar (r at angle theta) forms
Ignoring the quadrant when calculating phase angle from arctan
FAQs
What is a complex number?
How do I add complex numbers?
How do I multiply complex numbers?
What is the magnitude of a complex number?
What is the conjugate used for?
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