Electrical Calculators
Ohm's law, watts, amps, volts, wire size, voltage drop and electricity cost calculators.
18 calculators
- Amps to Watts CalculatorConvert amps to watts for DC, single-phase and three-phase AC using voltage and power factor. Get real power i
- Battery Life CalculatorEstimate how long a battery will last from its capacity in mAh or Ah and the load current, with a derating fac
- Capacitor Energy CalculatorCalculate the energy and charge stored in a capacitor from its capacitance and voltage. Supports pF, nF, µF, m
- Electricity Cost CalculatorCalculate how much it costs to run an appliance per day, month and year from its wattage, hours of use and you
- Generator Size CalculatorEstimate the generator size you need from the running watts of your appliances plus the surge of the largest m
- Horsepower to Amps CalculatorEstimate motor current from horsepower, voltage, efficiency and power factor for DC, single-phase and three-ph
- Kilowatts to Amps CalculatorConvert kW to amps for single-phase, three-phase or DC circuits, with a table of the current at common voltage
- kVA CalculatorConvert amps to kVA or kVA to amps for single-phase and three-phase power, and find kW from power factor. Hand
- LED Resistor CalculatorFind the current-limiting resistor for one LED or several in series from supply voltage, forward voltage and c
- Ohm's Law CalculatorOhm's law calculator: enter any two of voltage, current, resistance or power to find the other two, with every
- Power Factor CalculatorCalculate power factor, phase angle, kVA and kVAR from real power, voltage and current, and size the capacitor
- RC Time Constant CalculatorCalculate the RC time constant (tau) of a resistor-capacitor circuit, the time to charge to any percentage and
- Resistor Color Code CalculatorDecode 4-band and 5-band resistor color codes into resistance, tolerance and the minimum and maximum value. Pi
- Series and Parallel Resistor CalculatorCalculate the total resistance, capacitance or inductance of components in series and in parallel. Enter any n
- Voltage Divider CalculatorCalculate the output voltage of a two-resistor voltage divider, or find the bottom resistor for a target outpu
- Voltage Drop CalculatorCalculate voltage drop for copper or aluminum wire by AWG or kcmil size, length, current and phase. Shows volt
- Watts to Amps CalculatorConvert watts to amps for DC, single-phase and three-phase AC circuits using voltage and power factor. Shows t
- Wire Size CalculatorFind the right AWG copper or aluminum wire size for a load from ampacity tables at 60, 75 or 90 °C, with an op