kW to HP Converter

Convert kilowatts to horsepower — and back — using the standard that actually matches your equipment. This calculator covers all three horsepower types: Mechanical (the U.S./NEMA default), Metric / PS (the EU, Asia, and Latin America standard), and Electric (a narrower U.S. motor-rating convention). Enter a value to see the converted result, the exact formula used, and a chart comparing all three types side by side. A quick reference table and a full nameplate-reading guide are included below for students and job-site reference alike.

Use kW → HP to convert a kilowatt rating into horsepower, or HP → kW to go the other direction back into kilowatts.

Enter power in kilowatts. Formula: HP = kW ÷ conversion factor (factor depends on the type selected below).

Horsepower Type — Mechanical is the U.S. default

Mechanical (745.7 W)

The U.S. and Canadian standard (NEMA). Used on most North American motor and engine nameplates.

Metric / PS (735.5 W)

Used across the EU, Asia, and Latin America (IEC/ISO), and on most automotive spec sheets outside North America.

Electric (746.0 W)

A narrower U.S. convention for electric motor output ratings (IEC 60034). Nearly identical to Mechanical.

Power (kW) — select unit if not kilowatts

Mechanical HP

—

Metric HP (PS)

—

Electric HP

—

HP(elec)

Input Power

—

Formula: —

Horsepower Comparison

This chart shows what your entered power equals in all three horsepower types at once — useful because different equipment specs may use any of the three.

Mechanical Metric (PS) Electric

Results are for reference and estimation only. Verify all values before use in any electrical or mechanical design work. See full disclaimer below.

How to Use the kW to HP Converter

Select Conversion Direction

Choose kW → HP to convert kilowatts into horsepower, or HP → kW to go the other direction and convert horsepower back into kilowatts.

Select Horsepower Type

Choose Mechanical (the U.S./NEMA default), Metric / PS (used in the EU, Asia, and Latin America), or Electric (a narrower U.S. motor-rating convention). Each uses a slightly different watts-per-horsepower value — short definitions are shown right under the selector.

Enter Your Value

Type the kilowatt or horsepower value from the equipment nameplate or spec sheet into the input field. For kW → HP, you can also switch the unit to Watts or Megawatts.

Review Results and the Comparison Chart

Click Calculate. Results appear immediately — the converted value, the exact formula with substituted numbers, and a bar chart comparing all three horsepower types for your entered power. Use Print to capture results as they appear on screen for documentation.

Mechanical vs Metric vs Electric HP Comprehensive Guide

A deeper look at why "horsepower" isn't just one number, and how to read a motor nameplate correctly — written for students and job-site reference alike.

Mechanical Horsepower (745.7 W)

Also called Imperial horsepower, this is the standard used across the United States and Canada. It traces back to James Watt's original 18th-century comparison of steam engine output to the work of a draft horse, and was later codified by NEMA (the National Electrical Manufacturers Association) for U.S. motor nameplates. If a motor catalog is from a NEMA manufacturer, this is almost always the HP value being listed.

Metric Horsepower / PS (735.5 W)

Known as PS in German, CV in French and Spanish, this standard is used across the European Union, most of Asia, and Latin America. It's defined under ISO 1000 and DIN 66036, and is the figure you'll see on most automotive spec sheets published outside North America. It is about 1.4% smaller than mechanical horsepower — small per unit, but it adds up on larger motors.

Electric Horsepower (746.0 W)

Defined under IEC 60034, this is a narrower convention used specifically for electric motor output ratings in some North American contexts. It differs from mechanical horsepower by only about 0.04% — close enough that the two are often used interchangeably in practice, but it exists as its own defined standard.

Type	Watts per 1 HP	÷ Factor	Common Region / Standard	Typical Use
Mechanical	745.7 W	0.7457	U.S., Canada — NEMA MG1	NEMA motor nameplates
Metric (PS)	735.5 W	0.7355	EU, Asia, Latin America — ISO 1000	IEC motor & automotive specs
Electric	746.0 W	0.7460	N. America — IEC 60034	Electric motor output ratings

Reading a NEMA vs IEC Nameplate

NEMA-rated motors — common across the U.S. and Canada — list output power in horsepower directly on the nameplate, generally using the mechanical HP standard. IEC-rated motors — common across Europe, Asia, and most of the rest of the world — list output power in kilowatts on the nameplate, with metric horsepower used mainly in catalogs and automotive contexts rather than the nameplate itself. When matching a NEMA motor to an IEC replacement, convert using the mechanical HP formula; the two are close enough (within roughly 2%) that direct substitution usually works if voltage, frame size, and mounting also match.

Output Power vs Input Power

The kW or HP value on a nameplate is the rated output (shaft) power — the mechanical work the motor delivers. The actual electrical input power draw is always somewhat higher, because no motor is 100% efficient. For a motor that is roughly 90% efficient, input kW is approximately output kW divided by 0.90. This matters when sizing breakers, wiring, or a VFD — protection should be based on input current, not the nameplate HP or kW value alone.

This guide is provided for educational and reference purposes. Always confirm motor specifications against the actual manufacturer nameplate or datasheet before sizing, ordering, or installing equipment.

kW to HP Quick Reference Table

Common motor sizes in kilowatts, mapped to Mechanical and Metric horsepower, with a typical real-world application for each. Use this to sanity-check a calculated result at a glance.

kW	Mech. HP	Metric HP (PS)	Typical Application
0.25	0.335	0.340	Fractional pumps, small fans, HVAC dampers
0.37	0.496	0.503	Bench grinders, small compressors (≈½ HP class)
0.55	0.738	0.748	Sump pumps, sewing machines (≈¾ HP class)
0.75	1.006	1.020	Residential pool pumps (≈1 HP class)
1.5	2.012	2.039	Garage door openers, grain augers (≈2 HP class)
2.2	2.951	2.991	Drill presses, small compressors (≈3 HP class)
5.5	7.376	7.478	Centrifugal pumps (≈7.5 HP class)
11	14.752	14.956	HVAC chillers, large blowers (≈15 HP class)
22	29.503	29.912	Conveyor drives (≈30 HP class)
55	73.759	74.779	Industrial mixers, mine ventilation fans (≈75 HP class)

Frequently Asked Questions

How many HP is 1 kilowatt?

1 kW equals 1.341 mechanical horsepower, 1.360 metric horsepower (PS), or 1.340 electric horsepower. Divide kW by the relevant conversion factor — 0.7457 for mechanical, 0.7355 for metric, 0.746 for electric — to get the exact value for each type.

What is the difference between mechanical, metric, and electric horsepower?

Mechanical HP equals 745.7 watts and is the U.S./Canada NEMA standard. Metric HP (PS) equals 735.5 watts and is used across the EU, Asia, and Latin America. Electric HP equals 746.0 watts, a narrower U.S. convention for electric motor ratings. The gap between mechanical and metric is about 1.4%; between mechanical and electric it's only about 0.04%. See the full Comparison & Nameplate Guide above for a side-by-side breakdown.

Should I use mechanical or metric horsepower for my motor?

Use mechanical HP for NEMA-rated motors common in the U.S. and Canada. Use metric HP (PS) for IEC-rated motors common in Europe, Asia, and Latin America. The Comparison & Nameplate Guide above explains how to tell which standard your equipment's nameplate is using.

How do I convert horsepower back to kilowatts?

Multiply HP by the conversion factor instead of dividing: kW = HP × 0.7457 for mechanical, × 0.7355 for metric, or × 0.746 for electric. Switch this calculator to the HP → kW tab to do this automatically — just select the correct horsepower type first.

Why do different kW to HP calculators give slightly different results?

Most often it's because one calculator used mechanical HP and another used metric HP — a real 1.4% difference, not a rounding error. On a small motor that's negligible, but on a 200 kW motor it's nearly 3 HP. Always confirm which horsepower standard a result is using before comparing it to another source.

Is the kW to HP conversion exact?

Yes, mathematically — each horsepower type has a fixed watt-equivalent, so the math is exact. However, a real motor's actual output can differ from its nameplate value due to load conditions and efficiency losses, so always verify with measured data before relying on a conversion for critical sizing decisions.