Decibels Calculator (dB / dBm / dBi)
dBm, Watts, dBW conversion, EIRP, link attenuation, cable losses, and antenna gain calculations.
Power input
Quick presets:20 DBM
Potência em dBm
20.00 dBm
Potência em Watts
0.1000 W
Potência em Milliwatts
100.000 mW
Potência em dBW
-10.00 dBW
EIRP calculation (effective isotropic radiated power)
Calculated total EIRP:
30.50 dBm
Quick reference:
0 dBm = 1.0 mW (fiber / laser)
10 dBm = 10 mW
20 dBm = 100 mW (Wi-Fi example)
30 dBm = 1.0 W (point-to-point)
36 dBm = approximately 4.0 W
40 dBm = 10 W
-10 dBm = 0.1 mW
-30 dBm = 1.0 µW (RX sensitivity)
How to use this tool
Use dBm for power relative to 1 mW and watts for absolute power. The converter applies the logarithmic relationship and helps you check signal gains and losses.
Worked example
20 dBm equals 100 mW, or 0.1 W. 30 dBm equals 1 W. A 10 dB increase represents ten times the power.
Interpreting the result
dB is a ratio; dBm and dBW are power references. Antenna gain in dBi is not a transmitter power value.