Decode a resistor's color bands into its resistance and tolerance, or the reverse — type a value to get the bands.
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.
Battery Life Calculator
Estimate how long a battery lasts from its capacity and the device's average or sleep and active current, and size series and parallel packs.