How to use it
- Choose the conversion direction.
- Enter the value for the selected direction.
- Convert to view dBm, watts and milliwatts together.
dBm to Watt Calculator
Convert logarithmic dBm power values to watts and milliwatts, or convert watts back to dBm.
About the dBm to Watt Calculator
dBm expresses absolute power on a logarithmic scale referenced to one milliwatt.
Formula
Watts equal 10 raised to ((dBm - 30) / 10). In reverse, dBm equals 10 times log10 of milliwatts.
Common conversions
0 dBm equals 1 mW, 10 dBm equals 10 mW and 30 dBm equals 1 W.
Notes
A watt input must be greater than zero because the logarithm of zero is undefined.