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