Convert Power from Horsepower (British) to Milliwatts (hp to mW)

Horsepower (British) to Milliwatt Conversion Formula

Example

Let's convert 5 Horsepower (British) (hp) to Milliwatt (mW).

Using the formula:

Therefore, 5 Horsepower (British) (hp) is equal to 3728499.359312973638 Milliwatt (mW).

How many horsepower (british) are in one milliwatt? One Milliwatt (mW) contains 0.0000013410220890909090909 Horsepower (British) (hp) — the inverse of the factor above. Multiplying by 745699.87186259472759 takes you from horsepower (british) to milliwatts; multiplying by 0.0000013410220890909090909 brings you back.

Put in words: one horsepower (british) equals 745699.87186259472759 milliwatts, so the horsepower (british) is the larger unit of this pair. Converting between them never changes the amount of power being measured — only the size of the unit you count it in.

What Is British Horsepower (hp)?

British horsepower (hp) is a unit used to measure power, most commonly in the imperial system of measurement.

It was initially created to describe the amount of work a horse could do over a period of time.

In simple terms, one horsepower is defined as the power needed to lift 550 pounds by a distance of one foot in just one second.

Where Did the Term 'Horsepower' Come From?

The concept of horsepower was invented by Scottish engineer James Watt in the late 18th century.

To help sell his new steam engines, he needed a simple way to compare their power to something people already understood: the strength of a draft horse.

After observing horses at work, Watt calculated that an average horse could lift 550 pounds at a rate of one foot per second.

He established this value as the standard for one horsepower (hp), creating a brilliant marketing tool that is still used today.

What Can One Horsepower Actually Do?

It can be hard to picture what "550 foot-pounds per second" feels like. Here's a more modern way to think about it:

Imagine lifting a 55-pound bag of dog food 10 feet into the air in just one second.

The power you would need to do that is roughly equal to one horsepower.

This simple standard created a practical way to measure and compare the power of different engines and motors.

How to Convert Horsepower (hp) to Watts (W)

In modern science and most parts of the world, the standard unit for power is the watt (W), named after James Watt.

The conversion between horsepower and watts is essential for comparing specifications on modern electronics and machinery.

The conversion is:

• 1 Horsepower (hp) = 745.7 Watts (W)

This means an engine rated at 10 hp has a power output of approximately 7,457 watts, or about 7.5 kilowatts (kW).

What is a Milliwatt (mW)?

A milliwatt (mW) is a unit used to measure power.

It is equal to one-thousandth of a watt.

To put it simply, you need 1,000 milliwatts to equal one watt (1 W = 1,000 mW).

What Are Milliwatts Used For?

The milliwatt (mW) is the perfect unit for measuring the small amount of power used by many common electronic devices.

For example, the power of a Wi-Fi signal, the laser in a Blu-ray player, and the tiny LEDs on your electronics are all measured in milliwatts.

Using such small amounts of power is key to making the batteries last longer in your favorite gadgets, including wireless earbuds, smartwatches, and TV remotes.

How Do You Convert Milliwatts? (mW to Watts and dBm)

While the most common conversion is between milliwatts and watts (1,000 mW = 1 W), some technical fields use a different unit.

In telecommunications and fiber optics, power is often measured in dBm (decibels relative to one milliwatt). This scale makes it easier to work with a vast range of power levels.

For reference, 0 dBm is equal to exactly 1 mW.

Why Milliwatts (mW) Are Important for Laser Safety

When it comes to products with lasers, the milliwatt (mW) rating is a critical safety measure.

To prevent eye injuries, regulatory bodies like the FDA classify lasers based on their power output in milliwatts.

For example, handheld laser pointers sold to the public are legally required in most regions to have a power output of less than 5 mW.

This is a clear example of how milliwatt ratings are used to keep consumers safe.

Horsepower (British) to Milliwatt Conversion Table

Here are some quick reference conversions from Horsepower (British) (hp) to Milliwatt (mW):