Electrical engineering calculators
Calculate voltage, current, resistance, power and battery quantities with traceable SI equations.
Enter known quantities, select the target, then verify limits with manufacturer data.
Calculators in this category
Ohm's law: voltage, current and resistance
Calculate the missing electrical quantity from two known values and check power.
Open calculator →Electrical power from voltage and current
Determine a load's electrical power from voltage and current.
Open calculator →Electrical energy from power and time
Calculate appliance energy use from rated power and operating time.
Open calculator →Convert watts to amperes
Determine operating current from power and supply voltage for fuse and cable sizing.
Open calculator →Resistors in series
Determine total resistance of resistors connected in series.
Open calculator →Resistors in parallel
Calculate equivalent resistance of parallel branches for current sharing and protection sizing.
Open calculator →Voltage divider with two resistors
Determine unloaded output voltage from input voltage and resistor ratio.
Open calculator →Conductor resistance from material and geometry
Calculate DC resistance of a homogeneous conductor from resistivity, length and area.
Open calculator →Three-phase AC power
Calculate real power of a balanced three-phase system from line voltage, current and power factor.
Open calculator →Transformer turns ratio
Calculate secondary voltage or turns ratio of an ideal transformer.
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