In electronics and biomedical systems, power is often expressed in microwatts for ultra-low-power devices. But when scaling up to slightly higher power levels, such as portable electronics, communication modules, or precision instruments, it’s more practical to use milliwatts.
This guide explains how to convert microwatts to milliwatts with clear formulas, tables, and examples.
Definitions of Watt, Microwatt, and Milliwatt
Let’s get started by understanding the key definitions of Watt (W), Microwatt (µW), and Milliwatt (mW). Understanding these terms will allow you to perform conversions confidently.
What is Watt?
Watt (W) is the SI derived unit of power, named after James Watt, the Scottish engineer who improved the steam engine. It measures the rate of energy transfer per unit time.[1]
Mathematically 1 W = 1 j/s:
Where:
j = jouleunit of energys = secondunit of time
According to SI prefixes[2], which are based on powers of 10, a watt (1 W) is equivalent to one thousand milliwatts (103 mW or 1,000 mW) or one million microwatts (1,000,000 µF).
It is widely used to quantify electrical, mechanical, and thermal power in everyday applications such as light bulbs, appliances, and motors.
What is a Microwatt (µW)?
A microwatt (µW) is a unit of power in the International System of Units (SI) equal to one millionth (1/1,000,000) of a watt (0.000001 W).
Microwatt is used to express extremely small power levels, often in microelectronics, biomedical devices, and ultra-efficient sensors.
What is a Milliwatt (mW)?
A milliwatt (mW) is a unit of power in the SI system equal to one thousandth (1/1,000) of a watt (0.001 W).
Milliwatts are commonly used to measure small power levels in electronics and communication systems. Devices such as laser pointers, wireless transmitters, hearing aids, and portable audio equipment often operate in the milliwatt range, making this unit ideal for expressing precise, low-power outputs.
µW to mW formula
Let’s take a closer look at the conversion formula so you can carry out these conversions independently, whether using a calculator or doing it manually with pencil and paper.
The micro- prefix in the International System of Units (SI) corresponds to a multiplier of 10-6 (0.000001) while the milli- prefix represents 10-3 (0.001).
To convert microwatts (µW) to milliwatts (mW), divide the power value in microwatts by 1,000.
P(mW) = P(µW) ÷ 1,000
Or remember the µW-to-mW conversion factor: 1 µW = 0.001 mW
µW to mW conversion table
The conversion table below provides a handy reference for converting power measurement units from microwatts (µW) to milliwatts (mW). It covers commonly available power values, allowing for easy and quick conversions between these units of measurement.
| Microwatts (µW) | Milliwatts (mW) |
|---|---|
| 1 µW | 0.001 mW |
| 100 µW | 0.1 mW |
| 500 µW | 0.5 mW |
| 1,000 µW | 1 mW |
| 2,000 µW | 2 mW |
| 4,000 µW | 4 mW |
| 5,000 µW | 5 mW |
| 10,000 µW | 10 mW |
| 20,000 µW | 20 mW |
| 30,000 µW | 30 mW |
| 40,000 µW | 40 mW |
| 50,000 µW | 50 mW |
| 60,000 µW | 60 mW |
| 70,000 µW | 70 mW |
| 80,000 µW | 80 mW |
| 90,000 µW | 90 mW |
| 100,000 µW | 100 mW |
| 200,000 µW | 200 mW |
| 500,000 µW | 500 mW |
| 800,000 µW | 800 mW |
| 1,000,000 µW | 1,000 mW |
Examples
Now, let's look at an example that illustrates the calculations required to convert from microwatts to milliwatts (µW to mW).
Example: Sensor Output Conversion
Suppose a biomedical sensor outputs 8,500 µW of power. For reporting, you want the value in milliwatts.
Solution
Since 1 mW = 1,000 µW, we can convert 8,500 µW to milliwatts by using the following formula:
Therefore, the sensor consumes 8.5 mW of power.
To solve the problem with our calculator, follow the steps below:
- Enter the value in microwatts: For this example, enter
8,500into theFrombox. - View the result: The converter instantly calculates and displays the equivalent value in milliwatts:
8.5 mW.
FAQs
Is 1 microwatt or 1 milliwatt larger?
A milliwatt (mW) is a thousand times larger than a microwatt (µW). Here are the relationships between the units:
1 mW = 103 = 1,000 µW1 µW = 10-3 = 1 ÷ 1,000 = 0.001 mW
How to convert from microwatts to milliwatts?
To convert power from microwatts (µW) to milliwatts (mW), follow these simple steps:
- Write down the power value in microwatts (µW).
- Divide it by
1,000. - The result is the power in milliwatts (mW).
Why do I need to convert microwatts to milliwatts?
Converting µW to mW is essential when scaling ultra-low-power measurements into more practical ranges for electronics, communication systems, and reporting.
You now know how to convert power units from microwatts (µW) to milliwatts (mW). You can quickly use our calculator to convert between the power measurement units to save time for future calculations.
