Motor formula tool
Horsepower and Amps Calculator
Estimate the formula relationship between motor horsepower and current; 10 HP at 480 V 3-phase is about 11.2 A before NEC FLC or nameplate FLA review.
Convert Horsepower and Amps
Estimate the formula relationship between motor horsepower and current from voltage, phase, efficiency, and power factor. A 10 HP at 480 V 3-phase estimate is about 11.2 A; compare NEC FLC and nameplate FLA before motor sizing.
Result
Amps
11.73 A
Result notes
Keep the entered values, assumptions, and result together when adding this calculation to job notes or submittal records. Final installation choices should align with the applicable code edition, equipment listing, manufacturer instructions, local amendments, and AHJ requirements.
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Related charts
HP to Amps Chart
Use this HP to amps chart: 10 HP at 480V 3-phase estimates 11.2A running current; compare nameplate FLA and NEC FLC before sizing.
Motor Full Load Amps Chart
Plan motor full-load amp work by separating table FLC, nameplate FLA, formula estimates, starting current, overloads, and branch-circuit protection.
Motor Power HP kW Chart
Use a motor power HP kW chart to document horsepower, mechanical output, electrical input, kVA, kVAR, power factor, efficiency, and current context after the calculator result.
Related guides
Motor Power Formula | 25 HP 480V = 28.6A
Use motor power formulas for HP to kW, torque, and 3-phase current: 25 HP at 480V, 92% efficiency, PF 0.85 gives 28.6A by formula.
Motor Starting Current Guide | DOL, Soft Starter, VFD
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Formula and field context
Estimate the formula relationship between motor horsepower and current; 10 HP at 480 V 3-phase is about 11.2 A before NEC FLC or nameplate FLA review.
Formula context
HP to Amps Chart
HP-to-amps is a motor load estimate, not a substitute for motor nameplate FLA or NEC motor full-load current workflows. A 10 HP at 480 V 3-phase motor estimates about 11.2 A with the chart assumptions. Use it early when reviewing a pump, fan, compressor, conveyor, or shop motor schedule, then move to the motor calculator with voltage, phase, efficiency, power factor, nameplate current, and starting-current context.
Formula
Single phase estimate: A = HP x 746 / (V x efficiency x PF). Three phase estimate: A = HP x 746 / (1.732 x VLL x efficiency x PF).Variables to keep with the result
- HP is mechanical horsepower.
- Efficiency is motor efficiency entered as a decimal.
- PF is motor power factor entered as a decimal.
- V or VLL is the voltage used by the motor connection.
Formula and assumptions
Electrical input current can be estimated from horsepower by converting HP to watts, then dividing by voltage, phase factor, power factor, and motor efficiency. The formula is useful for planning, but it is not the same as NEC table full-load current or actual nameplate FLA.
U.S. motor context
Electricians often need a reasonableness check when a motor nameplate, equipment schedule, or control panel note lists HP but not current. A 10 HP motor at 480 V three-phase estimates near 11.2 A in the chart context. Treat it as a formula estimate, not a final branch-circuit current.
When to use the full calculator
Move to the motor-current and full-load-current calculators when conductor sizing, overloads, breaker settings, starter sizing, or NEC motor rules matter. This worksheet stays limited to the HP and amp relationship.