A unit of gain equal to ten times the common (base 10) logarithm of the ratio of two power levels or 20 times the common logarithm of the ratio of two voltage or current levels.

0 dB	x1
1 dB	x1.25
2 dB	x1.58
3 dB	x2
4 dB	x2.5
5 dB	x3.2
6 dB	x4
7 dB	x5
8 dB	x6.4
9 dB	x8
10 dB	10