# Horsepower Converter > Convert between different horsepower units including mechanical, metric, electrical, and boiler horsepower **Category:** Conversion **Keywords:** horsepower, hp, power, conversion, metric, mechanical, watts, kilowatts, engine **URL:** https://complete.tools/horsepower-converter ## How it calculates The tool uses established formulas to perform conversions between different horsepower and power units. Here’s how the relationships break down: 1 mechanical horsepower (hp) equals 550 foot-pounds per second (ft·lbf/s), 1 metric horsepower (PS) equals 735.5 watts (W), and 1 kilowatt (kW) is 1,000 watts (W). To convert horsepower to watts, you can apply this formula: Power (W) = Horsepower (hp) × 745.7. So, 745.7 is the number of watts in one mechanical horsepower. If you need to convert watts back to horsepower, use: Horsepower (hp) = Power (W) ÷ 745.7. In these equations, horsepower is your input, while watts are the output. This makes switching between different power units seamless. ## Who should use this This tool is perfect for automotive engineers figuring out engine power outputs, HVAC technicians assessing system efficiencies in kilowatts, and marine engineers converting horsepower ratings for boat engines. It’s also a great resource for industrial equipment operators who need to convert power ratings for machinery specs in both metric and imperial systems. ## Worked examples Let’s look at a couple of examples. Example 1: Consider when you need to convert 100 mechanical horsepower to watts. Using our formula, Power (W) = Horsepower (hp) × 745.7, you substitute 100 hp. That gives you Power (W) = 100 × 745.7, which equals 74,570 W. So, 100 mechanical horsepower translates to 74,570 watts. This is crucial for engineers who need to evaluate machinery power ratings. Example 2: Now, suppose you want to convert 50 kilowatts to metric horsepower. First, convert kilowatts to watts: 50 kW is 50,000 W. Then, apply the conversion formula: Horsepower (hp) = Power (W) ÷ 745.7. Plugging in the numbers gives you Horsepower (hp) = 50,000 ÷ 745.7, which is about 67.1 hp. Therefore, 50 kW is roughly 67.1 metric horsepower—handy for checking generator outputs in different units. ## Limitations This tool assumes a straightforward conversion between units, so it doesn’t account for variations in measurement standards across regions. You might find that it doesn’t give precise results for very small horsepower values due to rounding errors. In some edge cases, particularly with extremely high power values, accuracy may suffer because of numerical precision limits. Also, keep in mind that unit definitions can vary slightly based on industry practices, which might lead to some discrepancies in conversions. ## FAQs **Q:** How is mechanical horsepower defined in terms of work? **A:** Mechanical horsepower is defined as the work done at a rate of 550 foot-pounds per second, which is about 745.7 watts. **Q:** What’s the difference between metric and mechanical horsepower? **A:** Metric horsepower is set at 735.5 watts, while mechanical horsepower is around 746 watts. This slight difference comes from historical measurement standards. **Q:** Can this tool convert other power units, like joules? **A:** No, this tool specifically focuses on horsepower and its conversions to watts and kilowatts, not other power units like joules. **Q:** Is the conversion from horsepower to kilowatts linear? **A:** Yes, the conversion from horsepower to kilowatts is linear, based on fixed conversion factors that make calculations straightforward. --- *Generated from [complete.tools/horsepower-converter](https://complete.tools/horsepower-converter)*