dBW to dBm Converter
Power · unit-converter
Convert dBW to dBm with a fixed input and output unit, step-by-step formula line, and reference tables. Linear units use SI watt definitions; mechanical hp uses 550 ft·lbf/s; BTU/h uses the IT BTU; dBm/dBW are logarithmic relative to 1 mW and 1 W. The full Power Converter also includes PS/CV, TR, kVA/MVA, and ft·lb/s.
Calculator
From: dBW (dbw)
To: dBm (dbm)
About dBW
dBW is a logarithmic power level relative to 1 W: P(W) = 10^(dBW/10). RF, microwave, and antenna work often use dBW with dBm.
About dBm
dBm is a logarithmic power level relative to 1 mW: P(W) = 10^((dBm − 30)/10). It is standard in RF and telecommunications; it is not a linear multiple of the watt.
How to convert decibels relative to 1 w (dbw) to decibels relative to 1 mw (dbm)
dBm/dBW are logarithmic power levels. P_W = 10^((dBm − 30) / 10), P_W = 10^(dBW / 10), and inverse mappings use 10 × log₁₀(·) with P_W > 0.
Examples
Example #1: Convert 10 dbw to dbm
10 dbw → 40 dbm
Example #2: Convert 30 dbw to dbm
30 dbw → 60 dbm
Summary
Both units are logarithmic dB power units (dBm/dBW). Map through watts for absolute conversion: first recover watts from the source dB level, then apply the target dB definition.
Relationship context
You are converting between logarithmic RF levels (dBm) (Decibels relative to 1 W (dBW)) and logarithmic RF levels (dBm) (Decibels relative to 1 mW (dBm)). Log units (dBm/dBW) use base-10 definitions relative to 1 mW or 1 W; linear units map through watts first, then to or from the selected log unit. Only strictly positive power in watts maps to a real dB power value.
Conversion tables
| dBW (dbw) | dBm (dbm) |
|---|---|
| 0.1 | 30.1 |
| 1 | 31 |
| 2 | 32 |
| 3 | 33 |
| 4 | 34 |
| 5 | 35 |
| 6 | 36 |
| 7 | 37 |
| 8 | 38 |
| 9 | 39 |
| dBW (dbw) | dBm (dbm) |
|---|---|
| 10 | 40 |
| 20 | 50 |
| 30 | 60 |
| 40 | 70 |
| 50 | 80 |
| 60 | 90 |
| 70 | 100 |
| 80 | 110 |
| 90 | 120 |
| 100 | 130 |