Horsepower is a unit of work established by James Watt who lived until 1819. Watt wanted to measure the amount of energy required to raise coal out of a coal mine and so he created 'horsepower' as the unit of measure.

How much is one horsepower? One horsepower is equivalent to 33,000 foot-pounds of work performed in one minute. To give you a better sense of one horsepower, we have provided a list of equivalences - one horsepower equals all of the following:

• lifting 33,000 pounds, 1 foot in one minute
• lifting 1 pound, 33,000 feet in one minute
• lifting 1000 pounds, 33 feet in one minute
• lifting 1000 pounds, 330 feet in ten minutes
• lifting 100 pounds, 33 feet in 6 seconds

Watt used the term 'horsepower', because he estimated that this captured the amount of work an strong horse could perform.

Horsepower has survived to this day as a way of expressing the power harnessed by automobiles and other engine-driven machines such as tractors and garden equipment. Modern cars typically have 125 to 200 horsepower, but some high-performance cars have upwards of 400 horsepower!

Watt's name is used for another unit of energy - the watt, which is a unit of measure for electricity. You can read our related article titled How much is a kilowatt hour? for more information. Interestingly, horsepower can be converted into watts: one horsepower is equivalent to 746 watts.