Appendix D: Conversion from Power or Voltage Ratios to Decibels


Voltage or Pressure Ratio
Power or Intensity Ratio
<--- - dB + --->
Voltage or Pressure Ratio
Power or Intensity Ratio
1.000
1.000
0
1.000
1.000
0.989
0.977
0.1
1.012
1.023
0.977
0.955
0.2
1.023
1.047
0.966
0.933
0.3
1.035
1.072
0.955
0.912
0.4
1.047
1.096
0.944
0.891
0.5
1.059
1.122
0.933
0.871
0.6
1.072
1.148
0.923
0.851
0.7
1.084
1.175
0.912
0.832
0.8
1.096
1.202
0.902
0.813
0.9
1.109
1.230
0.891
0.794
1.0
1.122
1.259
0.841
0.708
1.5
1.189
1.413
0.794
0.631
2.0
1.259
1.585
0.750
0.562
2.5
1.334
1.778
0.708
0.501
3.0
1.413
1.995
0.668
0.447
3.5
1.496
2.239
0.631
0.398
4.0
1.585
2.512
0.596
0.355
4.5
1.679
2.818
0.562
0.316
5.0
1.778
3.162
0.531
0.282
5.5
1.884
3.548
0.501
0.251
6.0
1.995
3.981
0.473
0.224
6.5
2.113
4.467
0.447
0.200
7.0
2.239
5.012
0.422
0.178
7.5
2.371
5.623
0.398
0.159
8.0
2.512
6.310
0.376
0.141
8.5
2.661
7.079
0.355
0.126
9.0
2.818
7.943
0.335
0.112
9.5
2.985
8.913
0.316
0.100
10
3.162
10.00
0.282
0.0794
11
3.55
12.6
0.251
0.0631
12
3.98
15.9
0.224
0.0501
13
4.47
20.0
0.200
0.0398
14
5.01
25.1
0.178
0.0316
15
5.62
31.6
0.159
0.0251
16
6.31
39.8
0.141
0.0200
17
7.08
50.1
0.126
0.0159
18
7.94
63.1
0.112
0.0126
19
8.91
79.4
0.100
0.0100
20
10.0
100.0
3.16 x 10-2
10-3
30
3.16 x 10
103
10-2
10-4
40
102
104
3.16 x 10-3
10-5
50
3.16 x 102
105
10-3
10-6
60
103
106
3.16 x 10-4
10-7
70
3.16 x 103
107
10-4
10-8
80
104
108
3.16 x 10-5
10-9
90
3.16 x 104
109
10-5
10-10
100
105
1010
3.16 x 10-6
10-11
110
3.16 x 105
1011
10-6
10-12
120
106
1012