Verification: factors follow standard unit definitions; round for display only.

Horsepower to kilowatts

Convert hp to kW when a US motor nameplate, automotive brochure, or pump datasheet lists mechanical horsepower but your utility bill, EV spec sheet, or IEC equipment catalog expects kilowatts.

Horsepower (hp) and kilowatts (kW) both measure power—the rate at which energy is transferred or converted. On this site, one mechanical horsepower is anchored to the watt via the shared power unit graph: 1 hp = 745.699871582 W, which is exactly 0.745699871582 kW because 1 kW = 1,000 W.

kW = hp × 0.745699871582  ·  equivalently   kW = hp × 745.699871582 ÷ 1,000

That factor comes from the classical mechanical definition 550 ft·lbf per second, converted through SI length and force. For display and shop-floor math, rounding to 0.746 kW per hp (or the shortcut hp × 0.75) is common. The calculator above uses the full constant from converters.js; the steps below match it.

Step-by-step conversion (worked example)

Convert 200 hp to kilowatts—a typical passenger-car peak rating on US spec sheets:

1. Write the formula: kW = hp × 0.745699871582
2. Multiply: 200 × 0.745699871582 = 149.139974316 kW
3. Round for display: 149.1 kW on a fleet summary or charger sizing brief

European brochures often quote 110 kW for a similar class of car; always confirm whether the source used mechanical hp, metric hp (PS), or already reported kW before comparing numbers.

Second worked example (fractional motor)

Convert 5 hp on a single-phase shop motor nameplate:

1. 5 × 0.745699871582 = 3.728499358 kW
2. Round: 3.73 kW input when sizing a VFD or breaker

Electrical installers still verify amps at your voltage and power factor; hp→kW is only the power-unit step, not a substitute for NEC or local wiring rules.

Quick mental estimate (no calculator)

For rough checks, multiply horsepower by 0.75. Example: 100 hp → 100 × 0.75 = 75 kW (exact: 74.57 kW). The 0.75 shortcut runs about 0.6% high versus the site factor—fine for comparing two engines on a lot, but use 0.7457 (or the calculator) when the result feeds a utility interconnect or generator nameplate match.

Horsepower to kilowatt conversion chart

Where horsepower → kilowatts comes up

• Automotive (US brochures vs EU kW): North American marketing still lists brake or crank horsepower; EU type-approval and charging specs use kW. Converting lets you compare a 300 hp claim (~224 kW) against a 250 kW DC fast-charge cap or hybrid motor output.
• Electric motors & drives: NEMA-style plates quote hp; VFDs, soft starters, and EU efficiency labels use kW. Convert the mechanical hp rating first, then apply motor efficiency and power factor in a separate electrical calculation.
• Appliances & HVAC: Legacy US furnace blowers, pool equipment, and compressor curves may list hp; heat-pump datasheets and utility demand charges are kW-based. Convert before summing loads on a panel schedule.
• Generators & PTO equipment: Portable gensets and agricultural PTO ratings often stay in hp; grid-tie paperwork and microgrid models want kW. Use the same hp family the manufacturer documented (usually mechanical hp in US industrial catalogs).

Kilowatts to horsepower

Convert kW to hp when an EU motor plate, solar inverter label, or EV charger spec lists kilowatts but your US maintenance log, pump curve, or automotive comparison still quotes horsepower.

Reverse the hp→kW relationship by dividing kilowatts by the same factor, or multiplying by its reciprocal. Both routes are equivalent on this site's unit graph.

hp = kW ÷ 0.745699871582  ·  equivalently   hp = kW × 1.3410220896

The reciprocal 1.341022… hp per kW is what you get from 1,000 ÷ 745.699871582. For mental math, multiply kW by 1.34 is a tight estimate.

Step-by-step conversion (worked example)

Convert 75 kW to mechanical horsepower—common for a commercial HVAC motor or compact EV drive:

1. hp = kW ÷ 0.745699871582
2. 75 ÷ 0.745699871582 = 100.576653 hp
3. Round for display: 100.6 hp (not the same as 75 metric PS—see below)

Second worked example (appliance nameplate)

Convert 7.5 kW on a European oven or kiln element rating:

1. 7.5 ÷ 0.745699871582 = 10.0576 hp
2. Round: 10.1 hp when filling in a US equipment comparison spreadsheet

Quick mental estimate (reverse direction)

Approximation: multiply kilowatts by 1.34. Example: 50 kW → 50 × 1.34 ≈ 67 hp (exact: 67.05 hp). Good for quick sanity checks; use the full divisor when the value feeds a procurement spec tied to this converter.

Kilowatt to horsepower conversion chart

Reverse conversion is essential when metric inverter datasheets feed US maintenance tickets still written in hp, or when you reconcile kW-based utility demand with hp-rated legacy assets on the same site.

US mechanical hp vs metric hp, common mistakes, and related tools

This site uses mechanical horsepower tied to 745.699871582 W. Confirm which hp a brochure means before comparing to kW, and keep shaft power distinct from electrical input power.

Horsepower vs kilowatts at a glance

US mechanical horsepower vs metric horsepower (PS / CV)

Mechanical horsepower (imperial, US customary engineering) is defined as 550 ft·lbf/s and equals 745.699871582 W—the value wired into this project's converter graph. Metric horsepower (PS, pferdestärke, or CV in some languages) uses 75 kg-force meters per second and is about 735.5 W (~1.4% lower than mechanical hp). A European ad claiming 150 PS is not the same as 150 mechanical hp; converted to kW on this site's basis, 150 mechanical hp ≈ 111.9 kW, while 150 PS ≈ 110.3 kW. Always read the fine print on which hp definition was used.

Automotive press still mixes brake horsepower (bhp), SAE net, and metric test procedures. hp→kW here is a unit conversion only—it does not resolve dynamometer standards or drivetrain losses. For watt-level SI work from first principles, see watts to horsepower.

Shaft power, electrical power, and efficiency

Motor nameplates list shaft horsepower; your panel sees electrical kilowatts at the terminals. Efficiency, power factor, and service factor sit between those numbers. Convert hp→kW for the mechanical rating first, then apply the manufacturer's efficiency curve—or measure with a meter—before sizing breakers or comparing to a 7.5 kW heater load.

Common mistakes to avoid

• Using 0.75 as an exact factor — fine for estimates (~0.6% high vs the site constant). On a 500 hp compressor train that is roughly 3 kW of error; use 0.745699871582 when the result appears on a contract or interconnect application.
• Confusing mechanical hp with metric PS — treat PS as a different watt anchor (~735.5 W) unless the source explicitly states US mechanical hp.
• Equating engine hp with electric motor kW one-to-one — thermal losses, turbocharging, and battery limits mean drivetrain kW available at the wheels may differ from a gasoline hp peak even after unit conversion.
• Mixing power (kW) with energy (kWh) — kilowatt-hours are energy; kilowatts are power. A 7.5 kW element running one hour consumes 7.5 kWh; do not label that as 7.5 kW “per hour” in technical writing.
• Ignoring power factor on AC loads — utility billing and conductor sizing may involve kVA; converting hp to kW does not replace power-factor correction math.
• Rounding each asset before summing a plant total — convert each nameplate at full precision, sum, then round once for the report header.

Exactness and round-trip verification

Because horsepower on this site is defined as a fixed watt multiple, the conversion is deterministic across the unit graph, not a measured approximation. Converting 100 hp → 74.570 kW → 100 hp should recover the original within floating-point limits. Sanity checks: 1 hp ≈ 0.746 kW, 1 kW ≈ 1.341 hp, 200 hp ≈ 149.14 kW.

Related power converters

For the inverse slug of this page, open kilowatts to horsepower. Nearby workflows: watts to kilowatts, kilowatts to watts, watts to horsepower, watts to megawatts, megawatts to kilowatts, and BTU/hour to watts.