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

**Formula**

**Voltage Ratio = V _{ratio} = 10^{PdB/20}**

where PdB is the deciBel value of the voltage ratio

**Notes**

- These formulas assume the input and output impedances are the same.
- V
_{ratio}is the ratio of two Root-mean-square voltage values (not the peak or average) - V
_{ratio}is 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 = 10
^{5} - 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.

PdB | Voltage Ratio |
---|---|

-100 | 0.00001 |

-99 | 1.12201845430196E-05 |

-98 | 1.25892541179417E-05 |

-97 | 1.41253754462276E-05 |

-96 | 1.58489319246111E-05 |

-95 | 1.77827941003892E-05 |

-94 | 1.99526231496888E-05 |

-93 | 2.23872113856834E-05 |

-92 | 2.51188643150958E-05 |

-91 | 2.81838293126445E-05 |

-90 | 3.16227766016838E-05 |

-89 | 3.54813389233575E-05 |

-88 | 3.98107170553497E-05 |

-87 | 4.46683592150963E-05 |

-86 | 5.01187233627272E-05 |

-85 | 5.62341325190349E-05 |

-84 | 6.30957344480193E-05 |

-83 | 7.07945784384137E-05 |

-82 | 7.94328234724282E-05 |

-81 | 8.91250938133746E-05 |

-80 | 0.0001 |

-79 | 0.000112201845430196 |

-78 | 0.000125892541179417 |

-77 | 0.000141253754462275 |

-76 | 0.000158489319246111 |

-75 | 0.000177827941003892 |

-74 | 0.000199526231496888 |

-73 | 0.000223872113856834 |

-72 | 0.000251188643150958 |

-71 | 0.000281838293126445 |

-70 | 0.000316227766016838 |

-69 | 0.000354813389233575 |

-68 | 0.000398107170553497 |

-67 | 0.000446683592150963 |

-66 | 0.000501187233627272 |

-65 | 0.000562341325190349 |

-64 | 0.000630957344480193 |

-63 | 0.000707945784384138 |

-62 | 0.000794328234724281 |

-61 | 0.000891250938133746 |

-60 | 0.001 |

-59 | 0.00112201845430196 |

-58 | 0.00125892541179417 |

-57 | 0.00141253754462275 |

-56 | 0.00158489319246111 |

-55 | 0.00177827941003892 |

-54 | 0.00199526231496888 |

-53 | 0.00223872113856834 |

-52 | 0.00251188643150958 |

-51 | 0.00281838293126445 |

-50 | 0.00316227766016838 |

-49 | 0.00354813389233575 |

-48 | 0.00398107170553497 |

-47 | 0.00446683592150963 |

-46 | 0.00501187233627272 |

-45 | 0.00562341325190349 |

-44 | 0.00630957344480193 |

-43 | 0.00707945784384138 |

-42 | 0.00794328234724281 |

-41 | 0.00891250938133746 |

-40 | 0.01 |

-39 | 0.0112201845430196 |

-38 | 0.0125892541179417 |

-37 | 0.0141253754462275 |

-36 | 0.0158489319246111 |

-35 | 0.0177827941003892 |

-34 | 0.0199526231496888 |

-33 | 0.0223872113856834 |

-32 | 0.0251188643150958 |

-31 | 0.0281838293126445 |

-30 | 0.0316227766016838 |

-29 | 0.0354813389233575 |

-28 | 0.0398107170553497 |

-27 | 0.0446683592150963 |

-26 | 0.0501187233627272 |

-25 | 0.0562341325190349 |

-24 | 0.0630957344480193 |

-23 | 0.0707945784384138 |

-22 | 0.0794328234724281 |

-21 | 0.0891250938133745 |

-20 | 0.1 |

-19 | 0.112201845430196 |

-18 | 0.125892541179417 |

-17 | 0.141253754462275 |

-16 | 0.158489319246111 |

-15 | 0.177827941003892 |

-14 | 0.199526231496888 |

-13 | 0.223872113856834 |

-12 | 0.251188643150958 |

-11 | 0.281838293126445 |

-10 | 0.316227766016838 |

-9 | 0.354813389233575 |

-8 | 0.398107170553497 |

-7 | 0.446683592150963 |

-6 | 0.501187233627272 |

-5 | 0.562341325190349 |

-4 | 0.630957344480193 |

-3 | 0.707945784384138 |

-2 | 0.794328234724282 |

-1 | 0.891250938133746 |

0 | 1 |

1 | 1.12201845430196 |

2 | 1.25892541179417 |

3 | 1.41253754462275 |

4 | 1.58489319246111 |

5 | 1.77827941003892 |

6 | 1.99526231496888 |

7 | 2.23872113856834 |

8 | 2.51188643150958 |

9 | 2.81838293126445 |

10 | 3.16227766016838 |

11 | 3.54813389233575 |

12 | 3.98107170553497 |

13 | 4.46683592150963 |

14 | 5.01187233627272 |

15 | 5.62341325190349 |

16 | 6.30957344480193 |

17 | 7.07945784384138 |

18 | 7.94328234724282 |

19 | 8.91250938133745 |

20 | 10 |

21 | 11.2201845430196 |

22 | 12.5892541179417 |

23 | 14.1253754462275 |

24 | 15.8489319246111 |

25 | 17.7827941003892 |

26 | 19.9526231496888 |

27 | 22.3872113856834 |

28 | 25.1188643150958 |

29 | 28.1838293126445 |

30 | 31.6227766016838 |

31 | 35.4813389233575 |

32 | 39.8107170553497 |

33 | 44.6683592150963 |

34 | 50.1187233627272 |

35 | 56.2341325190349 |

36 | 63.0957344480193 |

37 | 70.7945784384138 |

38 | 79.4328234724281 |

39 | 89.1250938133745 |

40 | 100 |

41 | 112.201845430196 |

42 | 125.892541179417 |

43 | 141.253754462275 |

44 | 158.489319246111 |

45 | 177.827941003892 |

46 | 199.526231496888 |

47 | 223.872113856834 |

48 | 251.188643150958 |

49 | 281.838293126445 |

50 | 316.227766016838 |

51 | 354.813389233575 |

52 | 398.107170553497 |

53 | 446.683592150963 |

54 | 501.187233627272 |

55 | 562.341325190349 |

56 | 630.957344480193 |

57 | 707.945784384138 |

58 | 794.328234724281 |

59 | 891.250938133746 |

60 | 1000 |

61 | 1122.01845430196 |

62 | 1258.92541179417 |

63 | 1412.53754462275 |

64 | 1584.89319246111 |

65 | 1778.27941003892 |

66 | 1995.26231496888 |

67 | 2238.72113856834 |

68 | 2511.88643150958 |

69 | 2818.38293126445 |

70 | 3162.27766016838 |

71 | 3548.13389233575 |

72 | 3981.07170553497 |

73 | 4466.83592150963 |

74 | 5011.87233627272 |

75 | 5623.41325190349 |

76 | 6309.57344480193 |

77 | 7079.45784384138 |

78 | 7943.28234724281 |

79 | 8912.50938133746 |

80 | 10000 |

81 | 11220.1845430196 |

82 | 12589.2541179417 |

83 | 14125.3754462276 |

84 | 15848.9319246111 |

85 | 17782.7941003892 |

86 | 19952.6231496888 |

87 | 22387.2113856834 |

88 | 25118.8643150958 |

89 | 28183.8293126445 |

90 | 31622.7766016838 |

91 | 35481.3389233575 |

92 | 39810.7170553497 |

93 | 44668.3592150963 |

94 | 50118.7233627272 |

95 | 56234.1325190349 |

96 | 63095.7344480193 |

97 | 70794.5784384137 |

98 | 79432.8234724282 |

99 | 89125.0938133746 |

100 | 100000 |