# Milliwatt Converters

> Convert milliwatts (mW) to watts, kilowatts, horsepower, BTU/hour, and other power units

**Category:** Conversion
**Keywords:** milliwatt, mw, power converter, watt, kilowatt, microwatt
**URL:** https://complete.tools/milliwatt-converters

## How it works

The conversion between milliwatts and other power units follows straightforward multiplication by the appropriate conversion factor. The tool first converts any input value to milliwatts as a base unit, then derives all other unit values from that base.

Key conversion formulas from milliwatts:

1. Milliwatts to Watts: W = mW x 0.001
2. Milliwatts to Kilowatts: kW = mW x 0.000001
3. Milliwatts to Microwatts: µW = mW x 1,000
4. Milliwatts to Nanowatts: nW = mW x 1,000,000
5. Milliwatts to Horsepower: hp = mW x 1.341 x 10⁻⁶
6. Milliwatts to BTU/hr: BTU/hr = mW x 3.41214 x 10⁻³
7. Milliwatts to Joules/second: J/s = mW x 0.001
8. Milliwatts to kcal/hr: kcal/hr = mW x 8.5985 x 10⁻⁴
9. Milliwatts to Megawatts: MW = mW x 10⁻⁹
10. Milliwatts to dBm: dBm = 10 x log10(mW)

The dBm conversion is logarithmic rather than linear. This means 0 dBm equals exactly 1 mW, 10 dBm equals 10 mW, 20 dBm equals 100 mW, and so on. Each increase of 3 dBm approximately doubles the power. When converting from dBm to milliwatts, the inverse formula is used: mW = 10^(dBm / 10).

## Common conversions

Here are some frequently needed milliwatt conversions:

1 mW = 0.001 W (watts)
1 mW = 0.000001 kW (kilowatts)
1 mW = 1,000 µW (microwatts)
1 mW = 1,000,000 nW (nanowatts)
1 mW = 0 dBm (decibel-milliwatts)
10 mW = 10 dBm
100 mW = 20 dBm
500 mW = 0.5 W = 26.99 dBm
1,000 mW = 1 W = 30 dBm

In telecommunications, typical Wi-Fi router output power ranges from 50 mW to 200 mW (17 to 23 dBm). Bluetooth Low Energy transmits at about 1 to 10 mW (0 to 10 dBm). Laser pointers commonly output between 1 mW and 5 mW.

## Who should use this

RF engineers measuring and specifying transmitter power levels in milliwatts or dBm. Telecommunications professionals working with signal power budgets in fiber optic and wireless systems. Electronics engineers designing low-power circuits for IoT devices, sensors, and wearables. Laser safety officers converting laser output power specifications between milliwatts and other units. Audio engineers working with microphone sensitivity and preamplifier power levels. Students studying electrical engineering or physics who need to convert between power units for coursework and laboratory experiments. Hobbyists building amateur radio equipment or working with small electronic projects where power consumption is measured in milliwatts.

## FAQs

**Q:** What is the relationship between milliwatts and dBm?


**A:** The dBm scale is a logarithmic measure of power referenced to 1 milliwatt. The formula is dBm = 10 x log10(power in mW). This means 0 dBm equals exactly 1 mW, 3 dBm is approximately 2 mW, 10 dBm is 10 mW, and 30 dBm is 1,000 mW (1 watt). The logarithmic scale is preferred in RF engineering because it simplifies gain and loss calculations to simple addition and subtraction.


**Q:** How many milliwatts are in one horsepower?


**A:** One mechanical horsepower equals approximately 745,700 milliwatts (745.7 watts). This means a milliwatt is an extremely small fraction of a horsepower, roughly 1.341 x 10⁻⁶ hp. The horsepower unit is primarily used for motors and engines, while milliwatts are used for electronic and optical power measurements.


**Q:** Can this tool convert negative dBm values?


**A:** Yes. Negative dBm values represent power levels below 1 milliwatt. For example, -10 dBm equals 0.1 mW, -20 dBm equals 0.01 mW, and -30 dBm equals 0.001 mW (1 microwatt). Negative dBm values are common when measuring received signal strengths in wireless communications.


**Q:** What is the difference between milliwatts and joules per second?


**A:** Joules per second is identical to watts, so 1 milliwatt equals 0.001 joules per second. The watt is defined as one joule of energy transferred per second. Both are valid SI units of power, but joules per second explicitly shows the relationship between energy and time.


**Q:** Why do some specifications use milliwatts while others use watts?


**A:** The choice of unit depends on the typical power range of the application. Milliwatts are used when dealing with small power levels common in electronics, telecommunications, and optics. Watts and kilowatts are used for larger-scale applications such as household appliances and industrial equipment. Using appropriate units avoids unwieldy numbers with many leading zeros or very large values.

---

*Generated from [complete.tools/milliwatt-converters](https://complete.tools/milliwatt-converters)*