What is milliwatt?
A milliwatt is a unit of power equal to one thousandth of a watt. It is used in low-power electronics, wireless communication systems, laser specifications, and medical device power ratings.
Real-world uses
Milliwatts measure the power of laser pointers (Class 1: <1 mW; Class 3B: up to 500 mW), Bluetooth radios (typically 1–100 mW), Wi-Fi transmitters, and fibre optic signals. They are used in optical communications, consumer electronics, and medical laser specifications.
History
Milliwatts became relevant as the miniaturisation era brought small electrical and optical devices into widespread use from the mid-20th century. Consumer electronics, telecommunications, and biomedical equipment all required power specifications at this sub-watt scale.
Common mistakes
Confusing milliwatts (mW) with microwatts (µW)—1 mW = 1,000 µW. Also, assuming all laser pointers operate at the same power level; safety regulations classify lasers by output power in mW, and even small increases can be hazardous to the eyes.
What is kilowatt?
A kilowatt is a unit of power equal to 1,000 watts. It is commonly used to rate electric motors, heating systems, solar panels, EV chargers, and industrial equipment.
Real-world uses
Kilowatts are used for rating home electrical systems, electric vehicle charging speeds (Level 2 chargers: 7–22 kW), solar panel array output, electric motors in appliances, and small generators. A typical household may have a peak demand of 3–10 kW.
History
As electricity supply systems expanded in the late 19th century, the kilowatt became the practical unit for measuring power demands and generation capacities beyond the range of single watts. Its adoption enabled standardised rating of motors, generators, and electrical infrastructure.
Common mistakes
Confusing kilowatts (kW, power) with kilowatt-hours (kWh, energy). A 7 kW EV charger running for 2 hours delivers 14 kWh of energy. Also, mixing up kW and kVA in electrical specifications—kVA is apparent power, not real power.
When is this conversion used?
Converting milliwatt to kilowatt is useful in the power domain when comparing values across different measurement standards or applying formulas that require a specific unit.
Worked examples
1 milliwatt = 0.000001 kilowatt
1 kilowatt = 1,000 watt
How to convert milliwatt to kilowatt
To convert milliwatt to kilowatt, multiply the value by 0.000001.
To convert kilowatt back to milliwatt, multiply by 1,000,000.
Measurement standards
The watt is the SI derived unit of power, defined as one joule per second (kg·m²/s³). Horsepower remains in widespread informal use, particularly in the automotive industry, but has no single universal definition across regions.
Did you know?
The human body at rest produces about 80 watts of power — roughly enough to keep an incandescent light bulb glowing. During intense exercise, a trained cyclist can sustain over 400 watts, and elite sprinters briefly exceed 2,000 watts.
Quick reference: milliwatt to kilowatt
| milliwatt | kilowatt |
|---|---|
| 0.1 | 1.000000e-07 |
| 0.5 | 5.000000e-07 |
| 1 | 0.000001 |
| 2 | 0.000002 |
| 5 | 0.000005 |
| 10 | 0.00001 |
| 25 | 0.000025 |
| 50 | 0.00005 |
| 100 | 0.0001 |
| 250 | 0.00025 |
| 500 | 0.0005 |
| 1,000 | 0.001 |
Common values
| milliwatt | kilowatt | |
|---|---|---|
| LED light bulb | 10,000 milliwatt | 0.01 kilowatt |
| Desktop computer | 300,000 milliwatt | 0.3 kilowatt |
| Microwave oven | 1,000,000 milliwatt | 1 kilowatt |
| Small car engine | 75,000,000 milliwatt | 75 kilowatt |
| Wind turbine (large) | 3.000000e+09 milliwatt | 3,000 kilowatt |
Available Power units
More milliwatt conversions
- Convert milliwatt to watt
- Convert milliwatt to kilowatt
- Convert milliwatt to horsepower (mechanical)
- Convert milliwatt to megawatt
- Convert milliwatt to gigawatt
- Convert milliwatt to microwatt
- Convert milliwatt to BTU per hour
- Convert milliwatt to kilocalorie per hour
- Convert milliwatt to ton of refrigeration
Assumption: horsepower values use mechanical horsepower.