Electrical
Horsepower to Amps Calculator
Estimate motor current from horsepower for single-phase and three-phase circuits using voltage, efficiency, and power factor. Includes kW mode, tables, and CSV export.
Motor Current (Amps) from Horsepower
Convert HP to running amps using AC power formulas. Compare single-phase and three-phase, and generate sizing tables.
Key formulas
Single-phase (estimated): I = (HP × 746) / (V × η × PF)
Three-phase (estimated): I = (HP × 746) / (√3 × V × η × PF)
If you treat HP as an electrical equivalent (not mechanical output), you can omit efficiency and power factor. In real motors, efficiency and PF usually matter.
Single-phase (estimated): I = (HP × 746) / (V × η × PF)
Three-phase (estimated): I = (HP × 746) / (√3 × V × η × PF)
If you treat HP as an electrical equivalent (not mechanical output), you can omit efficiency and power factor. In real motors, efficiency and PF usually matter.
Practical reminder
Overcurrent devices and wire size must follow your electrical code and consider inrush current, duty cycle, ambient temperature, conductor type, and installation method.
Overcurrent devices and wire size must follow your electrical code and consider inrush current, duty cycle, ambient temperature, conductor type, and installation method.