Free calculators for resistors, capacitors, Ohm's Law, LED circuits and more
Decode 4-band and 5-band resistors instantly
Decode 3-digit and 4-digit SMD resistor codes
Calculate total resistance or capacitance in circuits
Decode capacitor values from color codes or markings
Calculate V, I, R, P • enter any two values
Find the right resistor for your LED circuit
Calculate output voltage from resistor divider
Reactance, LC resonance, and energy storage
Frequency, period, wavelength, RC time constant
Calculate watts, amps, volts • AC & DC power
BJT base resistor and operating point calculator
Search specs, pinouts, how-to guides & calculators for any component