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Power Converter

HP • kW • W • BTU/hr • cal/s

Power Value ⓘ

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Enter a power value to convert

How to Use the Power Converter

Enter a power value — e.g. 100 for 100 horsepower, or 5000 for 5000 watts.
Select From unit — HP (US engine standard), kW (European/electric), W (appliances), BTU/hr (HVAC), or metric HP.
HP types note — this uses mechanical HP (US). Metric HP (PS/CV) = 735.499 W. Electrical HP = 746 W exactly. All differ slightly.
Results show HP, kW, W, BTU/hr all at once for easy comparison.

Benefits

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Vehicle Comparison

Compare US car specs (HP) with European car specs (kW) when researching imported vehicles.

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HVAC & Appliances

Convert BTU/hr to kW for air conditioners, heaters, and heat pumps. 1 ton cooling = 12,000 BTU/hr = 3.517 kW.

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EV Power

Electric vehicles are rated in kW. Convert to HP for familiar comparison — Tesla Model 3: 283 HP = 211 kW.

Power Conversion Guide — Horsepower, Kilowatts, Watts, BTU/hr

Power conversion is needed when comparing US vehicles (rated in HP) to European and electric vehicles (rated in kW), evaluating HVAC systems (BTU/hr vs kW), or understanding electrical appliances. The key conversion: 1 HP = 745.7 watts = 0.7457 kW. A 200 HP sports car = 149.14 kW. A Tesla Model 3 Performance at 450 HP = 335.6 kW.

HVAC: Air conditioners are rated in BTU/hr or "tons." 1 ton of cooling = 12,000 BTU/hr = 3.517 kW. A typical 2-ton AC = 24,000 BTU/hr = 7.03 kW. Electrical: a 100-watt lightbulb = 0.1 kW = 0.1341 HP. The average US home uses about 1.2 kW on average (10,500 kWh/year ÷ 8,760 hours). Solar panels are rated in watts: a 400W panel produces 400 Wh of energy per hour of full sun.

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Vehicle Power Reference

Economy car: 100–150 HP = 74.6–111.9 kW. Mid-size sedan: 180–250 HP = 134–186 kW. Sports car: 300–500 HP = 224–373 kW. Supercar: 600–1000 HP = 447–746 kW. Semi-truck: 400–600 HP.

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HVAC Reference

1 ton = 12,000 BTU/hr = 3.517 kW. 1.5 ton = 18,000 BTU/hr = 5.28 kW. 2 ton = 24,000 BTU/hr = 7.03 kW. 3 ton = 36,000 BTU/hr = 10.55 kW. 5 ton = 60,000 BTU/hr = 17.58 kW.

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Electrical Appliances

LED bulb: 9W = 0.009 kW. Hair dryer: 1,800W = 1.8 kW. Microwave: 1,000W = 1 kW. Electric oven: 5,000W = 5 kW = 6.7 HP. EV charger (Level 2): 7,200W = 7.2 kW = 9.7 HP.

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Renewable Energy

Home solar system: 6–10 kW peak. Wind turbine (residential): 5–10 kW. Large wind turbine: 3–15 MW = 3,000–15,000 kW. Hoover Dam output: 2,080 MW = 2.08 million kW = 2.79 million HP.

Power Conversion FAQ

How many watts in a horsepower? ▾

1 mechanical horsepower (HP) = 745.69987 watts ≈ 745.7 W. Therefore, 1 kW = 1,000 W = 1.34102 HP. Common car conversions: 100 HP = 74.57 kW. 200 HP = 149.14 kW. 300 HP = 223.71 kW. 400 HP = 298.28 kW. 500 HP = 372.85 kW. For EVs: Tesla Model 3 350 HP = 261 kW. The term "horsepower" was coined by James Watt in the 1780s to market steam engines — he calculated a horse could do 33,000 foot-pounds of work per minute.

What is the difference between US horsepower and metric horsepower? ▾

US mechanical HP = 745.699 W. Metric HP (PS in German, CV in French/Spanish) = 735.499 W — about 1.4% less. European car specs use metric HP (PS) while US specs use mechanical HP. So a German car listed at "300 PS" = 300 metric HP = 295.8 US HP = 220.6 kW. Electric HP = 746 W exactly. Boiler HP = 9,809.5 W (a much larger unit used in industrial settings).

How do you convert BTU/hr to kilowatts? ▾

1 BTU/hr = 0.000293071 kW. Conversely, 1 kW = 3,412.14 BTU/hr. Common HVAC conversions: 12,000 BTU/hr = 3.517 kW (1 ton of cooling). 18,000 BTU/hr = 5.28 kW. 24,000 BTU/hr = 7.03 kW. 36,000 BTU/hr = 10.55 kW. When buying an air conditioner or heat pump, divide the BTU/hr rating by 3,412 to get kW and compare with European energy labels.

How much horsepower does a human produce? ▾

A fit human can sustain about 0.1 HP (75 W) for extended periods. Elite cyclists can sustain 0.4–0.5 HP (300–370 W) for an hour. Tour de France riders peak at about 1 HP (746 W) during short bursts. Usain Bolt peaked at about 3.5 HP (2,619 W) during his 100m world record sprint. So a "100 HP" car has the equivalent of about 1,000 sustained human workers — which is why the industrial revolution was so transformative.