How Much Horsepower Does A Horse Have?

I recently bought a new truck for doing jobs around my homestead and bringing materials and things home, and a friend of mine (who’s much more knowledgeable about trucks than me) was talking to me about how I’d made a great choice.

One thing he mentioned was horsepower, and that instantly got me wondering.

Does horsepower equal just one horse?

It’s an old and odd measuring system to use so it can be very confusing for a lot of us, but I decided to look into it and find out for myself.

So, how much horsepower does a horse have?

The important thing to remember about horsepower is that’s about the force exerted by the horse. Horsepower measures power or the rate at which work is done. The maximum output of a horse at a given moment is actually around 14.9 horsepower, but over the course of the day, it does about a horsepower’s worth of work.

It can be very confusing and, in many ways, the very notion of horsepower is an entirely antiquated concept today.

The world of car manufacturers understands it well enough that, in that context, it’s a perfectly valid system of measurement.

Today, very few of us have a concept of how much work a horse can do in a day, so let’s try to break this down a bit.

Why is it called horsepower?

History is the best place to start with this question, and this will help us best explain it.

In the 18^th and 19^th Centuries, there lived a Scottish engineer and inventor named James Watt who had come up with a far more efficient and improved steam engine.

He needed a way to effectively pitch the product, as it represented a huge change to the way people had lived their lives for millennia.

So, Watt took an interest in horses that worked in factories, lifting and pushing heavy loads.

He set out to calculate the power of a single horse.

From what he saw, he calculated that one horsepower was equivalent to one horse completing 33,000 foot-pounds of work in one minute.

He measured this by seeing how much water a horse could raise in a minute, at an ordinary walking pace.

Then, once he had all this, he could compare his new unit of measurement with how much work his new steam engine would do, and it was exactly what he needed to get his invention off the ground.

People could understand the boost in efficiency much, much better if they understood how it compared with horses, which had driven human evolution for thousands of years.

So, with all that in mind, let’s look at what one horsepower actually represents.

Is 1 horse power equal to a horse?

How much horsepower a horse can exert depends on how we measure this.

Looked at the total work done over the course of a full day, it does equal roughly one horsepower.

This is how James Watt measured the work done, over a long period of time.

In terms of minute and individual exertions that a horse is capable of, one horse can actually exert as much as 15 horsepower in a single moment.

But obviously, that is the absolute maximum of which they’re capable.

They won’t exert 15 horsepower worth of energy on every action.

So, taken as an average over the course of the whole day, the horsepower of a single horse is about 1 horsepower.

Take ourselves as a comparison.

The horsepower of our own muscles is about 1/5^th of a horsepower.

However, at our maximum exertion over a very short period of time, we can put out as much as 5 horsepower.

How much horsepower is considered fast?

What about horsepower in cars, then?

It puts it into stark perspective how wonderful an invention the internal combustion engine is.

Typical cars in the U.S. have between 180-200 horsepower, which is plenty for most conventional vehicles.

So, you would need a great deal of horses pulling the average car all at the same time, at the peak of their exertion, in order to reach the speeds possible in even an ordinary car.

The average driver generally wouldn’t use a car with more than 300 horsepower.

So, in other words, anything above or approaching 300 horsepower is considered a very fast car.

That is, of course, unless it is a large vehicle like a truck, which needs extra horsepower to move at all.

We would need tens of thousands of horses working in totally unattainable harmony to pull our vehicles anywhere near as quickly as we drive them.

As confusing as horsepower might be to understand, this is certainly not difficult to understand for anyone.

So, horsepower is not as straightforward as you might imagine. I know I certainly thought that 1 horsepower was the amount of energy or power that a horse could exert in any given moment.

The truth is much more complex, though, and it makes a lot more sense when you understand the system was fashioned by someone who was trying to convince people to switch from workhorses to engines in the 19^th Century.