Electrical Formulas

Common electrical formulas including Ohm's Law, Electric Power, Electric Energy, and Electrical Motor calculations

FormulaDescriptionVariables
U = R × IElectrical Potential (Ohm's Law)U: Voltage (V), R: Resistance (Ω), I: Current (A)
U = P / IElectrical Potential from PowerU: Voltage (V), P: Power (W), I: Current (A)
U = √(P × R)Electrical Potential from Power and ResistanceU: Voltage (V), P: Power (W), R: Resistance (Ω)
I = U / RElectric Current (Ohm's Law)I: Current (A), U: Voltage (V), R: Resistance (Ω)
I = P / UElectric Current from PowerI: Current (A), P: Power (W), U: Voltage (V)
I = √(P / R)Electric Current from Power and ResistanceI: Current (A), P: Power (W), R: Resistance (Ω)
R = U / IElectric Resistance (Ohm's Law)R: Resistance (Ω), U: Voltage (V), I: Current (A)
R = U² / PElectric Resistance from Voltage and PowerR: Resistance (Ω), U: Voltage (V), P: Power (W)
R = P / I²Electric Resistance from Power and CurrentR: Resistance (Ω), P: Power (W), I: Current (A)
P = U × IElectric PowerP: Power (W), U: Voltage (V), I: Current (A)
P = R × I²Electric Power from Resistance and CurrentP: Power (W), R: Resistance (Ω), I: Current (A)
P = U² / RElectric Power from Voltage and ResistanceP: Power (W), U: Voltage (V), R: Resistance (Ω)
W = P × tElectric EnergyW: Energy (Ws, J), P: Power (W), t: Time (s)
P = W / tPower from Energy and TimeP: Power (W), W: Energy (Ws, J), t: Time (s)
μ = 746 × Php / Pinput_wElectrical Motor Efficiencyμ: Efficiency, Php: Output horsepower (hp), Pinput_w: Input power (W)
μ = 746 × Php / (1.732 × V × I × PF)Electrical Motor Efficiency (3-phase)μ: Efficiency, Php: Output (hp), V: Voltage (V), I: Current (A), PF: Power Factor
P3-phase = (U × I × PF × 1.732) / 1,000Electrical Motor Power (3-phase)P3-phase: Power (kW), U: Voltage (V), I: Current (A), PF: Power Factor
I3-phase = 746 × Php / (1.732 × V × μ × PF)Electrical Motor Current (3-phase)I3-phase: Current (amps), Php: Output (hp), V: Voltage (V), μ: Efficiency, PF: Power Factor
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Inputs

Results

Voltage-- V
Current-- A
Resistance-- Ω
Power-- W
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Energy-- J
Energy-- kWh
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Inputs

Results

3-Phase Power-- kW
Motor Efficiency--
Motor Current (3-phase)-- A