Electricity

Calculate voltage, current, resistance or power from any two known electrical values.

Calculate DC, single-phase AC and three-phase AC electrical power, apparent power, reactive power and power factor correction.

Calculate wire resistance from material, length, cross-sectional area and temperature, with optional voltage-drop estimates.

Calculate equivalent resistance for series or parallel resistors, estimate current and power, and decode resistor color bands or SMD markings.

Calculate equivalent resistance for resistors in parallel and find practical two-resistor combinations for a target value.

Calculate total resistance, voltage drops and power dissipation for resistors connected in series.

Estimate voltage drop, percent drop, conductor loss and recommended wire size for DC, single-phase and three-phase circuits.

Estimate appliance energy use in kWh and electricity cost from watts, hours per day, days per month, quantity and USD per kWh.

Calculate capacitance, charge, voltage, stored energy, series or parallel capacitor networks, and RC timing estimates.

Calculate electric current in amps from power and voltage, voltage and resistance, or power and resistance for DC and AC estimates.

Calculate electrostatic force, charge, distance, relative permittivity, electric field and potential for two point charges.

Estimate single-layer coil inductance, required turns, inductive reactance and LC resonance frequency.

Calculate RC time constant, capacitor charge/discharge voltage, cutoff frequency, impedance and simple low-pass or high-pass filter behavior.

Calculate resistive heat energy from current, resistance and time, with power, voltage, Wh and kWh conversions.

Estimate AWG wire size from current, voltage, run length, conductor material and allowable voltage drop.

Calculate the series resistor and resistor wattage for one or more LEDs from supply voltage, forward voltage and target current.