Watts to dBm conversion

• Watts to dBm conversion calculator
• How to convert watts to dBm
• Watt to dBm conversion table

Enter the power in watts and press the Convert button:

Enter watts:		W
dBm result:		dBm

dBm to watts conversion calculator ►

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

so

1W = 30dBm

Example

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 ►