dB to V/V Formula and Calculator

This tool calculates the Voltage Ratio (V/V) from its deciBel (dB) value.

🔄 Voltage Ratio to dB

Formula

Voltage Ratio = Vratio = V/V = 10PdB/20

where PdB is the deciBel value of the voltage ratio

Notes

  • These formulas assume the input and output impedances are the same.
  • Vratio is the ratio of two Root-mean-square voltage values (not the peak or average)
  • Since RMS voltage is always positive, Vratio is also always a positive number

Example Calculation

A ratio quantifies how many times one number contains another. For instance, a ratio of two voltages denoted V1:V2 = 5:1 means the voltage V1 is five times V2. Conversely V2 is one-fifth the value of V1. The voltage ratio is a linear value and has no units.

deciBel or dB expresses the ratio between two numbers on a logarithmic scale. It is useful for representing both large and small numbers.

The calculator on this page converts from a the ratio to its deciBel equivalent.

  • For a PdB value of 100 dB, the Voltage ratio is 100000 = 105
  • A PdB value of 1 dB gives a linear Voltage ratio of 1.12

dB values less than 0 dB have a ratio between 0 and 1. For instance, PdB = -10 dB gives a ratio of 0.316. The more negative the dB value, the closer to 0 the ratio.

Table of dB to Voltage Ratio

This table presents linear equivalent over the range -100 dB to +100 dB.

PdBV/V
-1000.00001
-991.12201845430196E-05
-981.25892541179417E-05
-971.41253754462276E-05
-961.58489319246111E-05
-951.77827941003892E-05
-941.99526231496888E-05
-932.23872113856834E-05
-922.51188643150958E-05
-912.81838293126445E-05
-903.16227766016838E-05
-893.54813389233575E-05
-883.98107170553497E-05
-874.46683592150963E-05
-865.01187233627272E-05
-855.62341325190349E-05
-846.30957344480193E-05
-837.07945784384137E-05
-827.94328234724282E-05
-818.91250938133746E-05
-800.0001
-790.000112201845430196
-780.000125892541179417
-770.000141253754462275
-760.000158489319246111
-750.000177827941003892
-740.000199526231496888
-730.000223872113856834
-720.000251188643150958
-710.000281838293126445
-700.000316227766016838
-690.000354813389233575
-680.000398107170553497
-670.000446683592150963
-660.000501187233627272
-650.000562341325190349
-640.000630957344480193
-630.000707945784384138
-620.000794328234724281
-610.000891250938133746
-600.001
-590.00112201845430196
-580.00125892541179417
-570.00141253754462275
-560.00158489319246111
-550.00177827941003892
-540.00199526231496888
-530.00223872113856834
-520.00251188643150958
-510.00281838293126445
-500.00316227766016838
-490.00354813389233575
-480.00398107170553497
-470.00446683592150963
-460.00501187233627272
-450.00562341325190349
-440.00630957344480193
-430.00707945784384138
-420.00794328234724281
-410.00891250938133746
-400.01
-390.0112201845430196
-380.0125892541179417
-370.0141253754462275
-360.0158489319246111
-350.0177827941003892
-340.0199526231496888
-330.0223872113856834
-320.0251188643150958
-310.0281838293126445
-300.0316227766016838
-290.0354813389233575
-280.0398107170553497
-270.0446683592150963
-260.0501187233627272
-250.0562341325190349
-240.0630957344480193
-230.0707945784384138
-220.0794328234724281
-210.0891250938133745
-200.1
-190.112201845430196
-180.125892541179417
-170.141253754462275
-160.158489319246111
-150.177827941003892
-140.199526231496888
-130.223872113856834
-120.251188643150958
-110.281838293126445
-100.316227766016838
-90.354813389233575
-80.398107170553497
-70.446683592150963
-60.501187233627272
-50.562341325190349
-40.630957344480193
-30.707945784384138
-20.794328234724282
-10.891250938133746
01
11.12201845430196
21.25892541179417
31.41253754462275
41.58489319246111
51.77827941003892
61.99526231496888
72.23872113856834
82.51188643150958
92.81838293126445
103.16227766016838
113.54813389233575
123.98107170553497
134.46683592150963
145.01187233627272
155.62341325190349
166.30957344480193
177.07945784384138
187.94328234724282
198.91250938133745
2010
2111.2201845430196
2212.5892541179417
2314.1253754462275
2415.8489319246111
2517.7827941003892
2619.9526231496888
2722.3872113856834
2825.1188643150958
2928.1838293126445
3031.6227766016838
3135.4813389233575
3239.8107170553497
3344.6683592150963
3450.1187233627272
3556.2341325190349
3663.0957344480193
3770.7945784384138
3879.4328234724281
3989.1250938133745
40100
41112.201845430196
42125.892541179417
43141.253754462275
44158.489319246111
45177.827941003892
46199.526231496888
47223.872113856834
48251.188643150958
49281.838293126445
50316.227766016838
51354.813389233575
52398.107170553497
53446.683592150963
54501.187233627272
55562.341325190349
56630.957344480193
57707.945784384138
58794.328234724281
59891.250938133746
601000
611122.01845430196
621258.92541179417
631412.53754462275
641584.89319246111
651778.27941003892
661995.26231496888
672238.72113856834
682511.88643150958
692818.38293126445
703162.27766016838
713548.13389233575
723981.07170553497
734466.83592150963
745011.87233627272
755623.41325190349
766309.57344480193
777079.45784384138
787943.28234724281
798912.50938133746
8010000
8111220.1845430196
8212589.2541179417
8314125.3754462276
8415848.9319246111
8517782.7941003892
8619952.6231496888
8722387.2113856834
8825118.8643150958
8928183.8293126445
9031622.7766016838
9135481.3389233575
9239810.7170553497
9344668.3592150963
9450118.7233627272
9556234.1325190349
9663095.7344480193
9770794.5784384137
9879432.8234724282
9989125.0938133746
100100000

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