Here is a conversion table from dBm (dB milliWatt) to Watt. dBm is used to measure the power, and is also capable to express both very large and very small values. An 3dB increase in level is equivalent to doubling the power.
How to calculate the dBm value:
How to calculate the milliWatt value:
Where:
X = Power in dBm
P = Power in milliWatt
| dBm | Watt | dBm | Watt | dBm | Watt | dBm | Watt | |||
|---|---|---|---|---|---|---|---|---|---|---|
| 0 | 1.0 mW | 10 | 10 mW | 20 | 100 mW | 30 | 1.0 W | |||
| 1 | 1.3 mW | 11 | 13 mW | 21 | 130 mW | 31 | 1.3 W | |||
| 2 | 1.6 mW | 12 | 16 mW | 22 | 160 mW | 32 | 1.6 W | |||
| 3 | 2.0 mW | 13 | 20 mW | 23 | 200 mW | 33 | 2.0 W | |||
| 4 | 2.5 mW | 14 | 25 mW | 24 | 250 mW | 34 | 2.5 W | |||
| 5 | 3.2 mW | 15 | 32 mW | 25 | 320 mW | 35 | 3.2 W | |||
| 6 | 4.0 mW | 16 | 40 mW | 26 | 400 mW | 36 | 4.0 W | |||
| 7 | 5.0 mW | 17 | 50 mW | 27 | 500 mW | 37 | 5.0 W | |||
| 8 | 6.0 mW | 18 | 60 mW | 28 | 600 mW | 38 | 6.0 W | |||
| 9 | 8.0 mW | 19 | 80 mW | 29 | 800 mW | 39 | 8.0 W |
How to calculate (V)SWR
[CP_CALCULATED_FIELDS id=”7″]
* ERP = Percentage of Effective Radiated Power
| SWR | Power Loss | ERP*, Output to antenna |
|---|---|---|
| 1.0:1 | 0.0 % | 100 % |
| 1.1:1 | 0.2 % | 99.8 % |
| 1.2:1 | 0.8 % | 99.2 % |
| 1.3:1 | 1.7 % | 98.3 % |
| 1.4:1 | 2.8 % | 97.2 % |
| 1.5:1 | 4.0 % | 96.0 % |
| 1.6:1 | 5.3 % | 94.7 % |
| 1.7:1 | 6.7 % | 93.3 % |
| 1.8:1 | 8.2 % | 91.8 % |
| 2.0:1 | 11.1 % | 88.9 % |
| 2.5:1 | 18.4 % | 81.6 % |
| 3.0:1 | 25.0 % | 75.0 % |
| 4.0:1 | 36.0 % | 64.0 % |
| 5.0:1 | 44.4 % | 55.6 % |
| 6.0:1 | 51.0 % | 49.0 % |
| 8.0:1 | 60.5 % | 39.5 % |
| 10.0:1 | 66.9 % | 33.1 % |
| 12.0:1 | 71.6 % | 28.4 % |
| 14.0:1 | 75.1 % | 24.9 % |
| 16.0:1 | 77.9 % | 22.1 % |
| 20.0:1 | 81.9 % | 18.1 % |
| 25.0:1 | 85.2 % | 14.8 % |
| 30.0:1 | 87.5 % | 12.5 % |
| 40.0:1 | 90.5 % | 8.5 % |
| 60.0:1 | 93.6 % | 6.4 % |
| 100.0:1 | 96.1 % | 3.9 % |
| 200.0:1 | 98.0 % | 2.0 % |
| 400.0:1 | 99.0 % | 1.0 % |
| 800.0:1 | 99.5 % | 0.5 % |