Electronics Calculators

Capacitive and Inductive Reactance, RC and RL Time Constants, LC Resonance

Work out reactance and time constants for capacitors and inductors, size a transformer from its voltages, and check that a set of speakers is a safe load for your amplifier.

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Capacitor And Inductor Calculator

Reactance, RC and RL time constants and LC resonant frequency.

Every Electronics tool

Capacitor And Inductor Calculator

Reactance, RC and RL time constants and LC resonant frequency.

Speaker Impedance Calculator

Total ohms for speakers in series, parallel or series-parallel.

Transformer Calculator

Turns ratio, secondary turns and primary current from two voltages.

Circuits on the bench

The capacitor and inductor calculator covers the sums behind filters, timers and tuned circuits: reactance at any frequency, RC and RL time constants, RC cut-off frequency, LC resonance, Q factor and bandwidth. The transformer calculator turns two voltages into a turns ratio, secondary turns, primary and secondary current and the heat lost at a given efficiency. The speaker impedance calculator adds up series, parallel and series-parallel wiring and checks the result against your amplifier's minimum load. For Ohm's law and resistor colour codes, use the linked tools in the calculators section, which work alongside these.