dBm Milliwatts, Watts & Voltage Conversion Chart

Conversion table to convert between dBm, Watts and voltage in a 50 Ω system.


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Decibels, dB - the basics     Decibels levels table     dBm to dBW & power conversion chart     dBm to watts and volts conversion chart     Nepers    


When working with RF power, it is often useful to know the voltage level for a given power.

The table below provides a chart to convert between dBm, watts and voltage - peak to peak in a 50Ω system.

Although voltage levels are unlikely to rise to significant levels which might cause damage for power levels measured in dBm, the voltages are often used in other calculations.

Three tables have been included. These have been chosen because the voltages move from readings measured in millivolts to those in volts. Also as the milliwatts change to watts, the change in the table is made.

dBm / millivolts / milliWatts conversion table

This conversion table charts the values for dBm against milliwatts and the relevant voltage expressed in millivolts.

It is applicable to many lower power applications.

dBm milliWatts Voltage
millivolts (p-p)
Voltage
millivolts (RMS)
-30 0.0010 20 7.1
-28 0.0016 25.2 8.9
-26 0.0025 31.7 11.2
-24 0.0040 40.0 14.2
-22 0.0063 50.2 17.8
-20 0.010 63.2 22.4
-18 0.016 79.6 28.2
-16 0.025 100 35.5
-14 0.040 126 44.7
-12 0.063 159 56.4
-10 0.100 200 71.0
-8 0.16 252 89.4
-6 0.25 317 112
-4 0.40 399 142
-2 0.63 502 178
0 1.00 632 224
2 1.58 796 282
4 2.51 4000 1420

dBm - milliwatts - Volts conversion table:-

This conversion table charts the values for dBm against milliwatts and the relevant voltage expressed in volts.

It is applicable to many medium power applications.

dBm milliWatts Voltage
Volts (p-p)
Voltage
Volts (RMS)
0 1.00 0.632 0.224
2 1.58 0.796 282
4 2.51 4.00 1.42
6 3.98 1.26 0.45
8 6.31 1.59 0.56
10 10 2.00 0.71
12 15.8 2.52 0.89
14 25.1 3.17 1.12
16 39.8 3.99 1.41
18 63.1 5.02 1.78
20 100 6.32 2.24
22 158 7.95 2.82
24 25.1 10.0 3.55
26 398 12.6 4.48
28 631 15.9 5.64
30 1000 20.0 7.10
32 1585 25.2 8.94
34 2510 31.7 11.2

dBm - Watts - Volts conversion table

This conversion table charts the values for dBm against milliwatts and the relevant voltage expressed in volts.

It is applicable to many high power applications.

dBm Watts Voltage
mV (p-p)
Voltage
mV (RMS)
30 1.00 20 7.10
32 1.58 25.2 8.94
34 2.51 31.7 11.3
36 3.98 40.0 14.1
38 6.31 50.2 17.8
40 10.0 63.2 22.4
42 15.9 79.6 28.2
44 25.1 100 35.5
46 39.8 126 44.7
48 63.1 159 56.4
50 100 200 71.0
52 159 252 89.4
54 251 317 112
56 398 399 142
58 631 502 178
60 1000 632 224
62 1585 796 282

These tables of dBm, dBW, watts and miliwatts to volts are useful to discover the voltages present. Converting from dBm and from the other values of dBW and watts to voltage, both peak to peak and RMS can be useful in many areas of RF design.

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