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Electrical & Electronics

Ohm's Law, power, resistance, and electrical unit-conversion calculators for circuit design and everyday electrical work.

Ohm's Law Calculator

Solve for voltage, current, or resistance using Ohm's Law (V = I × R), plus power.

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Amps to Volts Conversion Calculator

Convert current to voltage using resistance or power.

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Amps to Watts Calculator

Convert current to power using voltage or resistance.

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Joules to Volts Conversion Calculator

Convert energy to voltage using electric charge.

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Joules to Watts Conversion Calculator

Convert energy to power using elapsed time.

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Power Calculator

Find electrical power from voltage and current, current and resistance, or voltage and resistance.

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Power Factor Calculator

Find apparent power and power factor from real and reactive power.

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Voltage Divider Calculator

Find the output voltage across R2 in a two-resistor voltage divider.

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Voltage Drop Calculator

Find the voltage lost across a circuit's resistance from current and resistance.

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Volts to Amps Conversion Calculator

Convert voltage to current using resistance or power.

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Volts to Joules Conversion Calculator

Convert voltage to energy using electric charge.

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Volts to Watts Conversion Calculator

Convert voltage to power using current or resistance.

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Watts to Amps Calculator

Convert power to current using voltage or resistance.

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Watts to Joules Conversion Calculator

Convert power to energy using elapsed time.

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Watts to Volts Conversion Calculator

Convert power to voltage using current or resistance.

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#2 Gauge Wire

Calculate voltage drop, percent drop, diameter, and area for a 2 AWG copper or aluminum wire run.

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AWG to mm Calculator

Convert any American Wire Gauge (AWG) size to diameter in mm and inches, area in mm² and kcmil.

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SWG to mm Calculator

Look up the diameter and cross-sectional area for any Standard (British) Wire Gauge (SWG) size.

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Wire Gauge Calculator

Calculate wire resistance, voltage drop, and diameter for any standard AWG wire size, copper or aluminum.

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Resistor Calculator

Decode 4-band or 5-band resistor color codes into resistance, tolerance, and value range.

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eV to Volts Calculator

Convert energy in electron-volts (eV) and charge into voltage using the eV-to-volts relationship.

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Volts to eV Calculator

Convert a voltage and charge into an energy in electron-volts (eV).

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Watts-Volts-Amps-Ohms Calculator

Enter any two of watts, volts, amps, or ohms to instantly solve for the other two.

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Electricity Calculator

Calculate the energy used and cost of running a single appliance or device.

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Amps to kVA Calculator

Convert amps and voltage to kVA (apparent power) for single-phase and three-phase AC circuits.

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Amps to kW Calculator

Convert amps, voltage, and power factor to kW (real power) for single-phase and three-phase AC circuits.

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Amps to VA Calculator

Convert amps and voltage to VA (apparent power) for single-phase and three-phase AC circuits.

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kVA to Amps Calculator

Convert kVA and voltage to amps for single-phase and three-phase AC circuits.

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kVA to kW Calculator

Convert kVA to kW (real power) using the power factor.

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kVA to VA Calculator

Convert kVA to VA (volt-amps) instantly.

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kVA to Watts Calculator

Convert kVA to watts (real power) using the power factor.

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kW to Amps Calculator

Convert kW, voltage, and power factor to amps for single-phase and three-phase AC circuits.

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kW to kVA Calculator

Convert kW to kVA (apparent power) using the power factor.

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kW to VA Calculator

Convert real power in kilowatts to apparent power in volt-amps using power factor.

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kW to Volts Calculator

Find voltage from real power, current, and power factor for single-phase or three-phase AC circuits.

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VA to Amps Calculator

Convert apparent power (VA) to current in amps for single-phase or three-phase circuits.

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VA to kVA Calculator

Convert apparent power from volt-amps (VA) to kilovolt-amps (kVA).

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VA to kW Calculator

Convert apparent power (VA) to real power in kilowatts using power factor.

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VA to Watts Calculator

Convert apparent power (VA) to real power in watts using power factor.

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Volts to kW Calculator

Calculate real power in kilowatts from voltage, current, and power factor, single-phase or three-phase.

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Watts to kVA Calculator

Convert real power in watts to apparent power in kilovolt-amps using power factor.

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Watts to VA Calculator

Convert real power (W) to apparent power (VA) using a power factor, with a plain explanation of the difference.

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kW to kWh Calculator

Convert kilowatts and hours of use into total energy in kilowatt-hours (kWh).

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kWh to kW Calculator

Convert kilowatt-hours and hours of use into an average power draw in kilowatts.

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kWh to Watts Calculator

Convert kilowatt-hours and hours of use into an average power draw in watts.

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Watts to kWh Calculator

Convert watts and hours of use into total energy in kilowatt-hours (kWh).

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Electricity Bill Calculator

Estimate a total electricity bill from a list of appliances, their wattage, daily run time, and your rate per kWh.

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Energy Consumption Calculator

Calculate daily, monthly, and annual energy consumption in kWh from a device's wattage and run time.

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Energy Cost Calculator

Calculate the total electricity cost from a kWh usage figure, a rate per kWh, and an optional fixed service fee.

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Amps to Horsepower Calculator

Convert current, voltage, and power factor into mechanical horsepower for single-phase and three-phase AC motors.

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Amps to Kilovolt-Amps (kVA) Conversion Calculator

Convert amps and voltage to kVA (apparent power) for single-phase and three-phase AC circuits.

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Amps to Kilowatts (kW) Conversion Calculator

Convert amps, voltage, and power factor to kW (real power) for single-phase and three-phase AC circuits.

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Amps to Volt-Amps (VA) Conversion Calculator

Convert amps and voltage to VA (apparent power) for single-phase and three-phase AC circuits.

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Horsepower to Amps Calculator

Convert mechanical horsepower, voltage, and power factor into the current an AC motor draws.

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Horsepower to Kilovolt-Amps (kVA) Conversion Calculator

Convert mechanical horsepower to apparent power (kVA) using the power factor.

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Kilovolt-Amps (kVA) to Amps Conversion Calculator

Convert kVA and voltage to amps for single-phase and three-phase AC circuits.

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Kilovolt-Amps (kVA) to Horsepower Conversion Calculator

Convert apparent power (kVA) to mechanical horsepower using the power factor.

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Kilovolt-Amps (kVA) to Kilowatts (kW) Conversion Calculator

Convert kVA to kW (real power) using the power factor.

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Kilovolt-Amps (kVA) to Volt-Amps (VA) Conversion Calculator

Convert kVA to VA (volt-amps) instantly.

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Kilovolt-Amps (kVA) to Watts Conversion Calculator

Convert kVA to watts (real power) using the power factor.

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Kilowatts (kW) to Amps Conversion Calculator

Convert kW, voltage, and power factor to amps for single-phase and three-phase AC circuits.

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Kilowatts (kW) to Kilovolt-Amps (kVA) Conversion Calculator

Convert real power in kilowatts to apparent power in kilovolt-amps using the power factor.

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Kilowatts (kW) to Volt-Amps (VA) Conversion Calculator

Convert real power in kilowatts to apparent power in volt-amps using the power factor.

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Volt-amps (VA) to Amps Conversion Calculator

Convert apparent power in volt-amps to amps using voltage, for single-phase or three-phase circuits.

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Volt-Amps (VA) to Kilovolt-Amps (kVA) Conversion Calculator

Convert apparent power in volt-amps to kilovolt-amps instantly.

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Volt-amps (VA) to Kilowatts (kW) Conversion Calculator

Convert apparent power in volt-amps to real power in kilowatts using the power factor.

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Watts to Kilovolt-Amps (kVA) Conversion Calculator

Convert real power in watts to apparent power in kilovolt-amps using the power factor.

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Current Calculator

Solve for electric current, charge, or time using the current-as-charge-over-time relationship.

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Voltage Calculator

Solve for voltage, energy, or electric charge using the energy-per-charge definition of voltage.

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Wattage Calculator

Solve for average power, energy, or duration using the energy-over-time definition of power.

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Peak Voltage Calculator

Calculate a sine wave's peak voltage from its RMS or peak-to-peak voltage.

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Peak-to-Peak Voltage Calculator

Calculate a sine wave's peak-to-peak voltage from its peak or RMS voltage.

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RMS Voltage Calculator

Calculate a sine wave's RMS voltage from its peak or peak-to-peak voltage.

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2026 Electricity Cost Calculator

Add appliances with their own wattage, hours per day, and days used to estimate a whole-home electricity cost at your own rate per kWh.

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2026 Lighting Energy Cost Calculator

Estimate lighting energy cost from a list of bulbs by brightness and technology, with a built-in LED savings comparison.

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Amp-Hours (Ah) to Kilowatt-Hours (kWh) Conversion Calculator

Convert amp-hours to kilowatt-hours using a battery's voltage — Ah alone isn't an energy figure without it.

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Amp-Hours (Ah) to Watt-Hours (Wh) Conversion Calculator

Convert amp-hours to watt-hours using a battery's voltage, the unit most manufacturers and airlines actually compare.

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Kilowatt-Hours (kWh) to Amp-Hours (Ah) Conversion Calculator

Convert a kWh energy figure to amp-hours at a given voltage, for battery bank and wiring sizing.

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Kilowatt-Hours (kWh) to Kilowatts (kW) Conversion Calculator

Convert kilowatt-hours and hours of use into an average power draw in kilowatts.

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Kilowatt-Hours (kWh) to Watts Conversion Calculator

Convert kilowatt-hours and hours of use into an average power draw in watts.

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Kilowatts (kW) to Kilowatt-Hours (kWh) Conversion Calculator

Convert kilowatts and hours of use into total energy in kilowatt-hours (kWh).

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Milliamp-Hours (mAh) to Watt-Hours (Wh) Conversion Calculator

Convert milliamp-hours to watt-hours using a cell's nominal voltage — the unit airline battery limits are actually written in.

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Watt-Hours (Wh) to Amp-Hours (Ah) Conversion Calculator

Convert watt-hours to amp-hours at a given voltage, for sizing battery capacity from an energy spec.

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Watt-Hours (Wh) to Milliamp-Hours (mAh) Conversion Calculator

Convert watt-hours to milliamp-hours using a cell's nominal voltage, for comparing against mAh-labeled batteries.

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Watts to Kilowatt-Hours (kWh) Conversion Calculator

Convert watts and hours of use into total energy in kilowatt-hours (kWh).

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Capacitance Calculator

Solve for charge, capacitance, or voltage using Q = C × V, with unit choices for each.

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Capacitance to Charge Conversion Calculator

Convert a capacitance and voltage directly into stored charge using Q = C × V.

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Coulomb's Law Charge Calculator

Find the electrostatic force between two point charges and whether it's attractive or repulsive.

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LED Resistor Calculator

Calculate the series current-limiting resistor an LED needs, plus its power dissipation.

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Parallel Plate Capacitance Calculator

Calculate capacitance from plate area, separation, and dielectric material using C = ε₀ × εr × A ÷ d.

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Parallel Resistor Calculator

Calculate the total resistance of any number of resistors wired in parallel.

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Resistance Calculator

Calculate a conductor's resistance from its material, length, and cross-section using R = ρ × L ÷ A.

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Resistor Capacitor Circuit Calculator

Find an RC circuit's time constant and capacitor voltage during charging or discharging.

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RLC Impedance Calculator

Calculate a series RLC circuit's reactance, impedance, and phase angle from R, L, C, and frequency.

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Series and Parallel Capacitor Calculator

Calculate the combined capacitance of capacitors wired in series or in parallel.

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Series Resistor Calculator

Calculate the total resistance of any number of resistors wired in series.

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Charge Conversion Calculators

Convert electric charge between coulombs, millicoulombs, microcoulombs, nanocoulombs, and picocoulombs.

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Conductance Conversion Calculators

Convert electrical conductance between siemens, millisiemens, microsiemens, and kilosiemens.

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Electric Charge Conversion

Convert a charge value between coulombs and its millicoulomb, microcoulomb, nanocoulomb, and picocoulomb multiples.

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Electric Current Conversion

Convert electric current between kiloamps, amps, milliamps, and microamps.

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Electrical Conductance Conversion

Convert a conductance value between siemens and its millisiemens, microsiemens, and kilosiemens multiples.

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Electrical Inductance Conversion

Convert electrical inductance between henries, millihenries, microhenries, and nanohenries.

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Electrical Resistance Conversion

Convert electrical resistance between megaohms, kilohms, ohms, and milliohms.

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Inductance Conversion Calculators

Convert inductance between henries, millihenries, microhenries, and nanohenries.

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Mixed Electrical Unit Conversion

Convert between units for voltage, current, resistance, power, charge, capacitance, inductance, or conductance, all in one tool.

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Energy Conversion Calculators

Convert energy between joules, kilojoules, watt-hours, kilowatt-hours, calories, kilocalories, and BTU.

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Wire Ampacity Calculator

Look up NEC Table 310.16 base ampacity ratings for AWG copper or aluminum wire at 60°C, 75°C, or 90°C.

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Wire Size Calculator

Find the smallest AWG copper or aluminum wire size that meets a required ampacity under NEC Table 310.16.

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