Watt to Milliwatt Converter
Power · unit-converter
Convert Watt to Milliwatt with a fixed input and output unit, step-by-step formula line, and reference tables. Linear units use SI watt definitions; mechanical hp uses 550 ft·lbf/s; BTU/h uses the IT BTU; dBm/dBW are logarithmic relative to 1 mW and 1 W. The full Power Converter also includes PS/CV, TR, kVA/MVA, and ft·lb/s.
Calculator
From: Watt (w)
To: Milliwatt (mw)
About Watt
The watt is the SI unit of power (one joule per second). All linear units in this converter are defined by a fixed watt equivalent.
About Milliwatt
One milliwatt is one thousandth of a watt. Common in RF, fiber optics, and low-power electronics.
How to convert watts to milliwatts
1 watt is equal to 1000 milliwatt when both are expressed in watt-equivalents:
1 w = (1 W ÷ 0.001 W) mw = 1000 mw
1 W = 1,000 mW.
Each watt is defined as 1 W and each milliwatt as 0.001 W in this tool, so one w equals 1 ÷ 0.001 mw = 1000 mw.
Let d(w) be the numeric value in Watt (w), and d(mw) the value in Milliwatt (mw). Then:
d(mw) = d(w) × (1 / 0.001)
Equivalently, divide by how many w fit into one mw (watts per mw divided by watts per w):
d(mw) = d(w) ÷ 0.001
Or: milliwatt = watt ÷ 0.001
Examples
Example #1: Convert 1 w to milliwatt
1 w = 1 w × (1/0.001) mw = 1000 mw
1 w = 1 w ÷ 0.001 = 1000 mw
Intermediate watts: 1 W
Example #2: Convert 10 w to milliwatt
10 w = 10 w × (1/0.001) mw = 10000 mw
10 w = 10 w ÷ 0.001 = 10000 mw
Intermediate watts: 10 W
Summary
To convert Watt to Milliwatt, multiply the value in w by the ratio of watts per w divided by watts per mw. Equivalently: value_mw = value_w × (1 / 0.001). Numerically, 1 w equals 1000 mw.
Relationship context
Both units are SI / decimal power (watts and prefixes). Conversions use fixed watt factors, so results stay consistent with the definitions in this converter. The factor from Watt to Milliwatt is 1.000000e+3 (1 w = 1000 mw).
Conversion tables
| Watt (w) | Milliwatt (mw) |
|---|---|
| 0.1 | 100 |
| 1 | 1,000 |
| 2 | 2,000 |
| 3 | 3,000 |
| 4 | 4,000 |
| 5 | 5,000 |
| 6 | 6,000 |
| 7 | 7,000 |
| 8 | 8,000 |
| 9 | 9,000 |
| Watt (w) | Milliwatt (mw) |
|---|---|
| 10 | 10,000 |
| 20 | 20,000 |
| 30 | 30,000 |
| 40 | 40,000 |
| 50 | 50,000 |
| 60 | 60,000 |
| 70 | 70,000 |
| 80 | 80,000 |
| 90 | 90,000 |
| 100 | 100,000 |