Electrical Tools
Practical electrical engineering tools for electricians, engineers, and hobbyists. Calculate voltage, current, resistance and power using Ohm's law and the power wheel, decode 4, 5 and 6-band resistor color codes and vice versa, calculate proper resistor values and wattage for LED circuits, compute voltage divider output voltage, calculate capacitance, charge, energy and impedance, estimate battery runtime from mAh capacity and consumption, determine proper wire gauge by current, length and voltage drop, calculate power factor, real, reactive and apparent power, compute 555 timer output frequency and duty cycle, and calculate inductance, inductive reactance and stored energy.
Calculate power factor, real power, reactive power, apparent power, and phase angle for AC circuits from any two known values.
Calculate frequency, duty cycle, period, and component values for 555 timer IC circuits in astable and monostable modes.
Calculate capacitance, charge, energy, and reactance for capacitors, plus series and parallel combinations. SI unit prefixes with real-time results and formulas.
Calculate inductance, stored energy, inductive reactance, series/parallel combinations, and LC resonant frequency with quality factor.
Find the right wire gauge for your circuit from current, voltage, run length, and acceptable voltage drop, with AWG and mm² results.
Calculate output voltage for a two-resistor voltage divider, find the resistor needed for a target voltage with E24 suggestions, and analyze load effects.
Calculate Voltage, Current, Resistance, and Power instantly. Enter any 2 values and get the other 2 using Ohm's Law and the Power Wheel.
Decode resistor values from color bands (4, 5, 6-band) or convert resistance values back to color codes instantly.
Estimate how long a battery will last from its capacity, current draw, and circuit efficiency, or find the capacity you need for a target runtime.
Find the right current-limiting resistor for your LED circuit, with the nearest E24 value, color code, power rating, and a live diagram for single, series, or parallel LEDs.