Learn Updated 2026-03-01 UTC

Complex Number Calculator — GetCalcMaster

Compute with complex numbers in rectangular or polar form. Keep results, notes, and intermediate steps together in a notebook.

Complex arithmetic with verification

The Complex Number Calculator helps you work in rectangular form (a + bi) and polar form (r∠θ). It supports common operations (conjugate, magnitude, argument, powers/roots) so you can verify algebra and build intuition for signals, control, and electromagnetics.

Open the tool

Example inputs to test

  • (3+4i)*(1-2i)11 - 2i
  • sqrt(-1)i (principal root)
  • conj(3+4i)3 - 4i
  • abs(3+4i)5
  • arg(1+i)π/4 (≈ 0.785398… radians)
  • cis(45) in DEG mode → 0.7071 + 0.7071i

Rectangular ↔ polar workflow

  • Rectangular → polar: compute r = abs(z) and θ = arg(z).
  • Polar → rectangular: compute r * cis(θ) and compare with a+bi.

Worked guides: Rectangular → polar and Polar → rectangular.

Common pitfalls

  • Angle mode: functions that interpret angles (cis, sin, cos) depend on DEG/RAD mode.
  • Branch cuts: complex sqrt, ln, and fractional powers use principal values. If you expect a different branch, compare against polar form and note the angle.
  • Formatting: switch between rectangular/polar output to confirm magnitude/phase agree.

Verification habit

A reliable manual check is: compute abs(z) and arg(z), then reconstruct using abs(z) * cis(arg(z)). The reconstructed value should match the original (up to rounding).

FAQ

Why do I see a different angle than another tool?

Angles can differ by multiples of 2π (or 360°). Many tools report a principal angle in a specific range. Convert both angles into the same range and compare.

Can I use this for phasors?

Yes, for educational checks. Enter magnitude/phase in polar form, convert to rectangular, and verify multiplications/divisions match expected phase addition/subtraction.