Capacitor Impedance Calculator Formula

Understand the math behind the capacitor impedance calculator. Each variable explained with a worked example.

Formulas Used

Capacitive Reactance (Xc)

reactance = 1 / (2 * pi * frequency_hz * cap_f)

Variables

VariableDescriptionDefault
capacitance_ufCapacitance(µF)10
frequency_hzFrequency(Hz)1000
cap_fDerived value= capacitance_uf / 1000000calculated

How It Works

Capacitive Reactance

Xc = 1 / (2 x pi x f x C)

Reactance decreases with frequency: capacitors pass high frequencies and block low frequencies (DC).

Worked Example

10 uF capacitor at 1 kHz.

capacitance_uf = 10frequency_hz = 1000
  1. 01C = 10 uF = 0.00001 F
  2. 02Xc = 1 / (2 x pi x 1000 x 0.00001)
  3. 03Xc = 1 / 0.06283 = 15.92 ohms

Ready to run the numbers?

Open Capacitor Impedance Calculator