What is the difference between horsepower and power?
5 Answers
Power is measured in kilowatts, and both horsepower and kilowatts are units of power, but there is a difference between the power represented by 1 horsepower and 1 kilowatt. Here is the relevant information: 1. The conversion between horsepower and power is 1 horsepower equals 735 watts or 0.735 kilowatts. The United States and the United Kingdom commonly use imperial horsepower, where 1 horsepower equals 0.985 imperial horsepower. Horsepower has been abolished from China's legal measurement units, and now engine power is labeled in kilowatts. 2. Horsepower is a commonly used unit of power in engineering, proposed by James Watt. 1 horsepower is approximately equal to 735 watts. It generally refers to metric horsepower rather than imperial horsepower. Power refers to the amount of work done by an object per unit of time, meaning power is a physical quantity that describes how fast work is done.
The term 'horsepower' sounds cool, but essentially it's just a different way to express power. Power is measured in kilowatts using the international unit system, while horsepower was originally established to describe the working capacity of horses. When checking car specifications, 1 horsepower is roughly equal to 0.735 kilowatts. So when you hear a car has 200 horsepower, its actual power output is about 147 kilowatts. Interestingly, horsepower comes in metric and imperial versions - American cars use imperial horsepower, which is slightly larger by about 1.5%. Nowadays Chinese cars mainly use kilowatts in their specifications, but car enthusiasts still prefer talking in horsepower when discussing performance, as the bigger number sounds more impressive. Ultimately, both units describe how quickly an engine can output energy.
Actually, they are just two different scales for the same thing, like kilometers and miles both measuring distance. When repairing cars, I often notice many people can't tell them apart. Some car owners point to the manual and ask why the Japanese version lists 110 kW for the same car while the US version shows 150 horsepower. I explain: if you do the conversion carefully, 150 horsepower multiplied by 0.735 equals approximately 110. The key is that using horsepower as a unit has a historical anecdote. Two hundred years ago, Watt used the working capacity of horses turning millstones as a reference to promote steam engines, and it has been passed down since then. Nowadays, apart from the US which still insists on using horsepower, most countries use kilowatts for new car specifications. However, ordinary people still prefer horsepower when buying used cars to gauge the sense of acceleration.
Last time, I argued with a friend about electric vehicle motor parameters before finally understanding the difference. Power is a general concept, measured internationally in watts or kilowatts. For example, a phone charger labeled 20 watts indicates its power value. Horsepower, on the other hand, is a unit specifically designed for vehicles, emphasizing the output efficiency of the engine. By definition, the continuous power output of one horse is set as 1 horsepower, equivalent to 735 watts. Interestingly, standards vary by country—Germany uses metric horsepower, which is slightly smaller, while the UK uses imperial horsepower, which is slightly larger. Nowadays, automotive reviewers prefer direct conversions during tests because many sports car brochures use inflated horsepower figures to grab attention, whereas power values more accurately reflect energy conversion efficiency.
Simply put, horsepower is the exclusive nickname for power. In repair shops, engine output is measured in kilowatts, but customers always ask how many horsepower. I remember the conversion formula as a rhyme: multiply kilowatts by 1.36 to get horsepower. For example, my old car's engine has 88 kilowatts, multiplied by 1.36 equals 120 horsepower. In actual driving, the high-power push-back sensation corresponds to high horsepower values, but the different units can be confusing. For instance, a European car manual might list 135kW as equivalent to 184 horsepower, while the same model in the U.S. would simply label it as 184hp. A little-known fact: nowadays, electric vehicle battery power is often measured in kilowatt-hours, while traditional gasoline cars still use horsepower—more as a nostalgic tradition.
