How to convert dBW to dBm
dBm = dBW + 30Both are decibel scales with different reference levels, so they differ by a constant.
Worked examples
- −30 dBW−30 dBW → 0 dBm
- −3 dBW−3 dBW → 27 dBm
- 6 dBW6 dBW → 36 dBm
- 30 dBW30 dBW → 60 dBm
- 50 dBW50 dBW → 80 dBm
DBW to dBm conversion table
Values are calculated by the conversion engine using the full formula and rounded to 8 significant figures.
| DBW (dBW) | DBm (dBm) |
|---|---|
| −60 dBW | −30 dBm |
| −40 dBW | −10 dBm |
| −30 dBW | 0 dBm |
| −20 dBW | 10 dBm |
| −10 dBW | 20 dBm |
| −3 dBW | 27 dBm |
| 0 dBW | 30 dBm |
| 3 dBW | 33 dBm |
| 6 dBW | 36 dBm |
| 10 dBW | 40 dBm |
| DBW (dBW) | DBm (dBm) |
|---|---|
| 13 dBW | 43 dBm |
| 20 dBW | 50 dBm |
| 23 dBW | 53 dBm |
| 27 dBW | 57 dBm |
| 30 dBW | 60 dBm |
| 33 dBW | 63 dBm |
| 37 dBW | 67 dBm |
| 40 dBW | 70 dBm |
| 50 dBW | 80 dBm |
| 60 dBW | 90 dBm |
About the units
Decibel-watt (dBW)
Power level relative to 1 W: dBW = dBm − 30. It is a logarithmic level: 0 dBW corresponds to 1 W.
Decibel-milliwatt (dBm)
Power level relative to 1 mW: 0 dBm = 1 mW, 30 dBm = 1 W, −30 dBm = 1 µW. It is a logarithmic level: 0 dBm corresponds to 0.001 W.
Frequently asked questions
What is the formula to convert dBW to dBm?
dBm = dBW + 30. Both are decibel scales with different reference levels, so they differ by a constant.
What is −3 dBW in dBm?
−3 dBW = 27 dBm.
Is this dBW to dBm converter accurate?
Yes. Both units are defined exactly in terms of SI units, so the conversion factor is exact; results are shown to 12 significant figures by default and you can change precision in the converter. Calculations run in your browser using the same tested engine that generated this page.