KW to HP Conversion Chart

Q: How do I match an imported kW motor to a NEMA HP frame size?

Look up the IEC kilowatt rating in the conversion table and read across to the nearest standard NEMA horsepower frame class. For example, a 7.5 kW motor maps to a standard 10 HP frame, and a 37 kW motor maps to a 50 HP frame.

Standard lookup table from 1 kW to 300 kW, interactive mini-calculator, and 3-phase electric motor power calculation guide.

Quick Calculator HP = kW × 1.34102

Kilowatts (kW)

Horsepower (HP)

100.58

Kilowatts to Horsepower Conversion Table

Standard commercial motor and generator ratings calculated using HP = kW × 1.34102.

Kilowatts (kW)	Horsepower (HP)	Standard Application / Frame
1 kW	1.34 HP	Fractional horsepower motor
1.1 kW	1.48 HP	Standard 1.5 HP nominal class
1.5 kW	2.01 HP	Standard 2 HP motor
2.2 kW	2.95 HP	Standard 3 HP motor
3.7 kW	4.96 HP	Standard 5 HP motor
5 kW	6.71 HP	Compact generator & pump
5.5 kW	7.38 HP	Standard 7.5 HP motor
7.5 kW	10.06 HP	Standard 10 HP motor
10 kW	13.41 HP	Commercial compressor
15 kW	20.12 HP	Standard 20 HP motor
20 kW	26.82 HP	Standard 25 HP class
25 kW	33.53 HP	Industrial hydraulic unit
30 kW	40.23 HP	Standard 40 HP motor
37 kW	49.62 HP	Standard 50 HP motor
40 kW	53.64 HP	Heavy water pump
45 kW	60.35 HP	Standard 60 HP motor
50 kW	67.05 HP	Commercial chiller compressor
55 kW	73.76 HP	Standard 75 HP motor
60 kW	80.46 HP	Industrial blower motor
75 kW	100.58 HP	Standard 100 HP motor
85 kW	113.99 HP	Automotive engine rating
90 kW	120.69 HP	Standard 125 HP motor
100 kW	134.10 HP	Heavy backup generator
110 kW	147.51 HP	Standard 150 HP motor
125 kW	167.63 HP	Industrial air compressor
150 kW	201.15 HP	Standard 200 HP motor / EV drive
175 kW	234.68 HP	Mining & municipal pump
200 kW	268.20 HP	Heavy plant prime mover
250 kW	335.26 HP	Standard 350 HP class
300 kW	402.31 HP	Standard 400 HP motor / EV powertrain

3-Phase KW to HP Conversion

When working with industrial three-phase induction motors, performing an accurate kw to hp conversion 3 phase calculation requires distinguishing between electrical input power supplied from the facility electrical distribution network and mechanical shaft output power delivered to the driven machine.

At a mechanical level, the mathematical relationship between mechanical shaft power in kilowatts and mechanical horsepower remains constant across both single-phase and three-phase motors: HP = kW × 1.34102. If a three-phase motor nameplate rates mechanical shaft output at 75 kW, its usable shaft mechanical rating is exactly 100.58 HP.

However, if you are measuring raw electrical parameters on an operating three-phase circuit (in either delta or wye configuration), total electrical power drawn from the line is calculated using the three-phase alternating current power formula:

kW = (√3 × Voltage × Current × Power Factor) ÷ 1,000

Where Voltage is line-to-line RMS voltage (e.g. 400V, 460V, or 480V), Current is line amperage, and Power Factor is cos(φ), typically between 0.82 and 0.89 under normal load.

Because motors do not convert 100% of electrical energy into mechanical movement due to copper losses, iron core hysteresis, and friction, motor internal efficiency (η) must be incorporated to calculate true mechanical shaft brake horsepower:

Shaft HP = (√3 × Voltage × Current × Power Factor × Efficiency) ÷ 745.7

Where Efficiency represents nominal motor efficiency (typically 88% to 96% on premium IE3 or IE4 induction motors).

Always remember that motor nameplates state mechanical output power, not electrical draw. Do not overclaim precision when estimating from line current alone, because operating power factor and efficiency vary substantially when motors operate under partial mechanical loads.

How to Use This Chart

This kw to hp chart serves as a fast workshop lookup table for electrical contractors, plant mechanics, and procurement engineers cross-referencing European IEC machinery with North American NEMA equipment.

Frame Size Matching: When sourcing a replacement for an imported machine, match the specified kilowatt rating to the standard nominal horsepower frame class (for example, a 7.5 kW motor maps directly to a standard 10 HP frame, and a 37 kW motor maps to a 50 HP frame).
Conductor & Breaker Sizing: Locate the corresponding horsepower value to look up required full load amps (FLA) in National Electrical Code (NEC) tables to verify conductor gauge and circuit protection.
VFD and Soft Starter Selection: Variable frequency drives must match both motor continuous kilowatt rating and maximum full-load amperage to withstand motor starting torque spikes.
Service Factor Verification: Check whether the target motor carries a 1.0 or 1.15 Service Factor (SF) before downsizing from a horsepower rating to the closest metric kilowatt equivalent.

If you are working with non-standard decimal values or need to convert horsepower back to kilowatts, use our full kW to HP calculator on the homepage for instant custom calculations.

Frequently Asked Questions About the KW to HP Chart

Common questions from electricians and plant engineers about using this kw to hp chart and 3-phase motor conversions.

How do I convert kW to HP for a 3-phase motor?

For mechanical shaft output, the formula is the same as single-phase: HP = kW × 1.34102. If you are calculating from raw electrical line readings instead, use kW = (√3 × Voltage × Current × Power Factor) ÷ 1,000, then apply motor efficiency to estimate true shaft horsepower.

What is the difference between electrical input power and mechanical shaft power?

Electrical input power is what the motor draws from the supply, measured in kW. Mechanical shaft power is the usable output after copper, iron, and friction losses. Motor nameplates list mechanical shaft output, not raw electrical draw, which is why efficiency must be factored into any conversion.

How do I match an imported kW motor to a NEMA HP frame size?

Look up the IEC kilowatt rating in the table above and read across to the nearest standard NEMA horsepower frame class. For example, a 7.5 kW motor maps to a standard 10 HP frame, and a 37 kW motor maps to a 50 HP frame.

Why does motor efficiency matter when converting kW to HP?

No motor converts 100% of electrical input into mechanical output. Premium IE3/IE4 induction motors typically run 88% to 96% efficient, so the true shaft horsepower delivered is always lower than a raw kW-to-HP conversion of electrical draw would suggest.

Can I use this chart to size a VFD or circuit breaker?

Use it as a starting reference only. Match the motor's kW and HP rating here, then confirm full-load amperage (FLA) from the manufacturer nameplate or NEC tables before sizing a VFD, soft starter, or circuit breaker — this chart does not replace nameplate FLA data.