Convert Power from British thermal units per second to Milliwatts (Btu/s to mW)

British thermal unit per second to Milliwatt Conversion Formula

Example

Let's convert 5 British thermal unit per second (Btu/s) to Milliwatt (mW).

Using the formula:

Therefore, 5 British thermal unit per second (Btu/s) is equal to 5275279.995421782416 Milliwatt (mW).

How many british thermal units per second are in one milliwatt? One Milliwatt (mW) contains 9.4781698873601257269× 10^-7 British thermal units per second (Btu/s) — the inverse of the factor above. Multiplying by 1055055.9990843564832 takes you from british thermal units per second to milliwatts; multiplying by 9.4781698873601257269× 10^-7 brings you back.

Put in words: one british thermal unit per second equals 1055055.9990843564832 milliwatts, so the british thermal unit per second 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 a British thermal unit per second (Btu/s)?

The British thermal unit per second (Btu/s) is a unit used to measure power in the imperial system of measurement.

Think of it as a way to quantify how much heat energy is being transferred in a single second. For context, one Btu/s is equal to about 778.17 foot-pounds per second (ft-lb/s).

The plural form is "British thermal units per second."

How to Convert Btu/s to Watts

A common question is how Btu/s relates to the watt, which is the standard (SI) unit of power. The conversion is straightforward and very useful for comparing equipment specifications.

• 1 Btu/s is equal to approximately 1,055.06 watts (W).
• This is the same as 1.055 kilowatts (kW).

This conversion is essential for anyone needing to compare the power of different systems, especially when analyzing energy use or heat output.

Where is Btu/s Used? Common Applications

You'll most often see Btu/s used in high-power industrial and scientific settings to measure the rate of heat energy transfer.

It's a key measurement for specifying the performance of powerful equipment, such as:

• Industrial boilers
• Large-scale heat exchangers
• Power plant turbines

While you might see Btu/h (Btu per hour) used for your home's HVAC system or water heater, Btu/s provides a much more detailed, second-by-second measurement needed for these high-capacity industrial applications.

Btu/s vs. Horsepower: What's the Connection?

In engineering, Btu/s is also directly related to horsepower (hp), another common imperial unit of power.

This connection is vital for understanding the thermal efficiency of engines—in other words, how well an engine converts heat into mechanical work.

The relationship is:

• Approximately 0.7068 Btu/s is equal to 1 mechanical horsepower (hp).

This allows engineers to compare the heat an engine produces (in Btu/s) to the mechanical power it puts out (in horsepower).

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.

British thermal unit per second to Milliwatt Conversion Table

Here are some quick reference conversions from British thermal unit per second (Btu/s) to Milliwatt (mW):