How Many Watts in 1 Horsepower

Edited By Team Careers360 | Updated on Mar 27, 2023 05:17 PM IST

Introduction

Power is the amount of energy converted per unit of time. Its SI(Système international or International System of Units) unit is Watt, equal to one joule per second. Whereas its other unit is horsepower (hp). As we know, in physics, units have a very important place in measurements. 1 Metre can not be equal to 1 centimeter, and 1 kilogram weight is not the same as 1 gram. Hence, they can not be added or subtracted together directly. We need to make them equal by adding more quantity in the smaller unit.

The same goes for watt and horsepower. Both are units of power but are used in different contexts. Horsepower is the unit that originated from Native English-speaking countries and is mainly used in automobile engineering to measure an engine's power. Watt is a widely used unit used to measure the power ratings of electrical appliances. Suppose we know the value of the power of an electric fan in watts, but we need the value in horsepower. So how will we convert them?

In this article, we will first learn the differences between watt and horsepower to make it easy for us to understand its conversion. Secondly, we will learn the value of a watt in 1 horsepower. Also, in the end, solving some questions will help us understand the concept better.

Differences Between Watt and Horsepower

There are differences given between watt and horsepower in the table below:

Watt	Horsepower
Watt is the SI unit of power	Horsepower is fps (foot-pound-second) unit of power
Mostly used for electrical systems	Mostly used for automobiles
Represented by symbol “W”	Represented by symbol “hp”

Relationship Between Watt and Horsepower

As we know the differences between watt and horsepower, we will now figure out the relationship between them.

From observations and experiments, scientists have figured out the relation between the value of hp and the value of watt, which is:

1 hp = 745.7 W

If we apply 1 hp of power, then we will say that it is equal to 745.7 W of power.

Solved Examples

Q1. An electrical appliance uses 64 hp of power. Convert the value of 64 horsepower into watt.

Ans: As we know that 1 hp = 745.7 W

On putting values we get:

\begin{equation}

64 hp=745.7 \times 64\

=47724.8 W

\end{equation}

Q2. Suppose there is a bulb with 400 W. Convert 400 watt into horsepower.

Ans: 1 W = 0.0013 hp

Now,

\begin{equation}

400 W=0.0013 \times 400\

=0.52 hp

\end{equation}

Frequently Asked Questions (FAQs)

1. Define one watt.

If a body performs 1 joule of work in 1 second, it is said to use 1 watt of power.

2. Why is watt more widely accepted than horsepower?

Watt is the SI unit, which means it’s noted internationally, whereas hp is the fps unit and is majorly used in English-speaking countries.

3. Name the other units of Power except for watt and horsepower.

Other units of Power include:

Units	Abbreviation
ergs per second	\begin{equation} \frac{erg}{s} \end{equation}
kilocalories per hour	\begin{equation} \frac{kcal}{h} \end{equation}
BTU or British Thermal Units per hour (used to measure the amount of heat content that is present in fuel-based energy sources)	\begin{equation} \frac{BTU}{h} \end{equation}