dBm to Watt Converter

Power · unit-converter

Convert dBm to Watt 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: dBm (dbm)

To: Watt (w)

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.

About Watt

The watt is the SI unit of power (one joule per second). All linear units in this converter are defined by a fixed watt equivalent.

How to convert decibels relative to 1 mw (dbm) to watts

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.

To reach Watt, convert dBm → W, then divide by the watt factor for w (1 W per 1 w).

Examples

Example #1: Convert 10 dbm to watt

10 dbm0.01 w

Example #2: Convert 30 dbm to watt

30 dbm1 w

Summary

To convert dBm to Watt, first convert dBm to watts: P_W = 10^((dBm − 30)/10). Then divide by the watt factor for w: value_w = P_W / 1.

Relationship context

You are converting between logarithmic RF levels (dBm) (Decibels relative to 1 mW (dBm)) and SI / decimal power (watts and prefixes) (Watts). 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

dBm (dbm)Watt (w)
0.10.001023293
10.0012589254
20.0015848932
30.0019952623
40.0025118864
50.0031622777
60.0039810717
70.0050118723
80.0063095734
90.0079432823
dBm (dbm)Watt (w)
100.01
200.1
301
4010
50100
601,000
7010,000
80100,000
901,000,000
10010,000,000