This tool converts from dBf (deciBel Femtowatt) to dBm (deciBel milliwatt) and Watt.
dBm = dBf – 120
PdBf = 10*log10(PfW)
1 Femtowatt = 10-15 Watt
1 Watt = 1015 Femtowatt
dBf is used to specify the sensitivity of Frequency Modulation (FM) Radio receivers. dBm is generally used for RF power measurements.