Electrical Calculators

Calculate voltage, current, resistance, or power using Ohms Law.

Calculate electrical power in watts from volts and amps.

Calculate power factor and reactive power for AC circuits.

Solve the power triangle: real, reactive, and apparent power.

Calculate output voltage of a resistor voltage divider.

Calculate electricity cost for any appliance by wattage.

Estimate total monthly electricity bill from appliance usage.

Calculate annual energy cost and savings from efficiency changes.

Decode resistor color bands and calculate resistance.

Calculate total resistance of resistors in parallel.

Find the correct resistor for any LED circuit.

Calculate capacitance, charge, and energy stored.

Calculate inductance, reactance, and energy stored.

Calculate voltage drop across a wire run.

Find the right circuit breaker size for any load.

Estimate how long a battery lasts under a given load.

Estimate solar energy output and system size needed.

Calculate horsepower from motor voltage, current, and efficiency.

Convert between horsepower, watts, and kilowatts.

Estimate engine horsepower from torque and RPM using the standard HP formula.

Calculate three-phase power, current, and power factor.

Find the correct wire gauge AWG for any current load.

Find the generator wattage needed to power your home or job site.

Calculate transformer turns ratio, voltage, and current.

Calculate BTUs needed to heat or cool a room.

Calculate network bandwidth, download time, and transfer rate.

Find the LED equivalent wattage for any incandescent bulb.

All-in-one electrical calculator: kWh, cost, amps, and more.