How to convert watts to dBm

The power conversion of watts to dBm is given by the formula:

P(dBm) = 10 · log10( 1000 · P(W) ) = 10 · log10( P(W) ) + 30so

1W = 30dBmExampleConvert 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

0.00001 W -20.0000 dBm

0.0001 W -10.0000 dBm

0.001 W 0.0000 dBm

0.01 W 10.0000 dBm

0.1 W 20.0000 dBm

1 W 30.0000 dBm

10 W 40.0000 dBm

 100 W 50.0000 dBm

 1000 W 60.0000 dBm

 10000 W 70.0000 dBm

100000 W 80.0000 dBm

1000000 W 90.0000 dBm

How to convert dBm to watts

1dBm = 0.001258925W

So the power conversion of dBm to watts is given by the formula:

P(W) = 10(P(dBm) 

/ 10) / 1000 = 10((P(dBm) 

- 30) / 10)

Example

Convert 43dBm to watts:

P(W) = 10(43dBm / 10) / 1000 = 19.9526W

dBm to watts conversion table

Power (dBm) Power (W)

-30 dBm 0.0000010 W

-20 dBm 0.0000100 W

-10 dBm 0.0001000 W

0 dBm 0.0010000 W

1 dBm 0.0012589 W

2 dBm 0.0015849 W

3 dBm 0.0019953 W

4 dBm 0.0025119 W

5 dBm 0.0031628 W

6 dBm 0.0039811 W

7 dBm 0.0050119 W

8 dBm 0.0063096 W

9 dBm  0.0079433 W

10 dBm 0.0100000 W

20 dBm 0.1000000 W

30 dBm 1.0000000 W

40 dBm 10.0000000 W

50 dBm  100.0000000 W