Find the series resistor for one or more LEDs, rounded up to a standard E-series value, with its power rating and actual current.
Voltage Divider Calculator
Work out a divider's output voltage, current and resistor power, or find R1 for a target voltage with the nearest E12, E24 and E96 values.
RC Time Constant Calculator
Get an RC circuit's time constant, charge curve and cutoff frequency, find R for a target cutoff, or an LC circuit's resonant frequency.