Watts to dBm
Type a value in W to get it in dBm instantly.
43.01dBm
That's 100× as strong as a phone transmitting, while a broadcast transmitter is 5,000× stronger. That is about 20,000 milliwatts.
Convert the other way: dBm to W
What it means
How strong is that signal?
Voltage figures assume the 50 ohm system impedance of radio equipment. In a 75 ohm cable television system the same power gives a different voltage.
The math
How to convert W to dBm
dBm is an absolute level against one milliwatt: mW = 10^(dBm ÷ 10), and dBm = 10 × log₁₀(mW). Add 30 for dBW, and in 50 ohms add 107 for dBµV.
Example: 20 W = 43.0103 dBm.
Every unit
Your level in every unit
Tables
W to dBm conversion table
| W | dBm |
|---|---|
| 1×10⁻¹³ W | -100 dBm |
| 1×10⁻¹⁰ W | -70 dBm |
| 1×10⁻⁸ W | -50 dBm |
| 1×10⁻⁶ W | -30 dBm |
| 0.0001 W | -10 dBm |
| 0.001 W | 0 dBm |
| 0.01 W | 10 dBm |
| 0.1 W | 20 dBm |
| 1 W | 30 dBm |
| 10 W | 40 dBm |
| 100 W | 50 dBm |
dBm to W conversion table
| dBm | W |
|---|---|
| -100 dBm | 1×10⁻¹³ W |
| -70 dBm | 1×10⁻¹⁰ W |
| -50 dBm | 1×10⁻⁸ W |
| -30 dBm | 1×10⁻⁶ W |
| -10 dBm | 0.0001 W |
| 0 dBm | 0.001 W |
| 10 dBm | 0.01 W |
| 20 dBm | 0.1 W |
| 30 dBm | 1 W |
| 40 dBm | 10 W |
| 50 dBm | 100 W |
Quick answers
Quick answers
- How many dBm is 1 W?
- 1 W is 30 dBm.
- How many dBm is 10 W?
- 10 W is 40 dBm.
- How many dBm is 20 W?
- 20 W is 43.0103 dBm.
The units
About these units
Watts (W)
For transmitters and amplifiers.
dBm (dBm)
Decibels relative to one milliwatt, the standard radio power level.
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