Watts to dBm free online conversion

Watts to dBm conversion calculator

Watts (W) to decibel-milliwatts (dBm), power conversion calculator.

Enter the power in watts and press the Convert button:


dBm to Watts Conversion »

How to convert watts to dBm

The power P(dBm) in dBm is equal to 10 times the base 10 logarithm of 1000 times the power P(W) in watts (W) divided by 1 watt (W):

P(dBm) = 10 ⋅ log10( 1000 ⋅ P(W) / 1W) = 10 ⋅ log10( P(W) / 1W) + 30


1W = 30dBm


Convert 20 watts to dBm:

P(dBm) = 10 ⋅ log10(1000⋅20W) = 43.0103dBm

Watt to dBm conversion table

Power (mW) Power (dBm)
0 W not defined
0+ W -∞ dBm
01 W -20 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
 1000 W 60 dBm
 10000 W 70 dBm
100000 W 80 dBm
1000000 W 90 dBm

dBm to Watts Conversion »

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