Decibel-milliwatt to Watt Converter
0 dBm is 0.001 W. Convert decibel-milliwatts (dBm) to watts (W) below: type a value and the result updates as you type.
dBm to W calculator
Result
Decibel-milliwatt to Watt conversion
1 dBm ≈ 0.001258925412 Wone decibel-milliwatt in watts
1 W = 30 dBmone watt in decibel-milliwatts
Decibel-milliwatt (dBm): Power level relative to one milliwatt: 10 times the base-10 logarithm of the power in milliwatts. 0 dBm is 1 mW and 30 dBm is 1 W.
Watt (W): SI derived unit: one joule per second.
Source:Decibel-milliwatt: IEC 60027-3:2002, Logarithmic and related quantities, and their units; Watt: SI Brochure, 9th edition (BIPM, 2019)
How to convert decibel-milliwatts to watts
To convert decibel-milliwatts to watts, divide the level by 10, raise 10 to that power, then multiply by 0.001.
Formula
W = 0.001 × 10^(dBm ÷ 10)
Examples
- 0 dBm = 0.001 × 10^(0 ÷ 10) = 0.001 W
- 20 dBm = 0.001 × 10^(20 ÷ 10) = 0.1 W
- 30 dBm = 0.001 × 10^(30 ÷ 10) = 1 W
Decibel-milliwatt to Watt conversion table
| Decibel-milliwatt (dBm) | Watt (W) |
|---|---|
| -60 dBm | 1e-9 W |
| -30 dBm | 0.000001 W |
| -20 dBm | 0.00001 W |
| -10 dBm | 0.0001 W |
| 0 dBm | 0.001 W |
| 3 dBm | 0.001995262315 W |
| 10 dBm | 0.01 W |
| 13 dBm | 0.01995262315 W |
| 20 dBm | 0.1 W |
| 23 dBm | 0.1995262315 W |
| 30 dBm | 1 W |
| 40 dBm | 10 W |
| 50 dBm | 100 W |
Values rounded to 10 significant digits where needed.
Frequently asked questions
- What is 0 dBm in W?
- 0 dBm is 0.001 W. To convert decibel-milliwatts to watts, divide the level by 10, raise 10 to that power, then multiply by 0.001.
- How do I convert watts to decibel-milliwatts?
- To convert watts to decibel-milliwatts, divide the amount by 0.001, take the base-10 logarithm, then multiply by 10. The formula is dBm = 10 × log₁₀(W ÷ 0.001).
- Is this conversion exact?
- Yes. Both units have exact definitions and the factor 0.001 is exact. Displayed results are only rounded when they have many decimal places.