NOTE: Attenuation expressed in decibels of relative power.
A 3 dB pad reduces power to one half, 6 dB to one fourth, 10 dB to one tenth, 20 dB to one hundredth, 30 dB to one thousandth and so on. For voltage you double the dBs so for example 6 dB is half in voltage.
EXAMPLE: Calculating 50 Watt Attenuator into dB:
3db: 50 x 0.50 = 25 watt; 6db: 50 x 0.25 = 12.5 watt; 10db: 50 x 0.10 = 5 watt; 20db: 50 x 0.01 = 0.5 watt; 30db: 50 x 0.001 = 0.05 watt; 40db: 50 x 0.0001 = 0.005 watt.
