dBm to Watts Conversion Calculator

dBm to Watts Calculator

Enter power in dBm:

Watts result: W

A dBm to Watts calculator converts power levels between decibel-milliwatts (dBm) and Watts (W), which are commonly used in RF engineering, telecommunications, networking, and electronics.

Key Definitions

Unit	Description
dBm	Logarithmic unit relative to 1 milliwatt (0.001 W)
Watts (W)	Absolute unit of power (base SI unit)

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Conversion Formula

The mathematical relationship between dBm and Watts is:

$$P_{(W)}={10}^{\left(\frac{P_{(dBm)}-30}{10}\right)}$$

Alternative Formula (via mW)

Since 1 W = 1000 mW, you can also:

1. First convert dBm → mW:

   $$P_{(mW)}={10}^{\left(\frac{P_{(dBm)}}{10}\right)}$$

2. Then convert mW → W:

   $$P_{(W)}=\frac{P_{(mW)}}{1000}$$

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Step-by-Step Conversion Example

Convert 40 dBm to Watts

1. Using direct formula:

   $$P_{(W)}={10}^{\left(\frac{40-30}{10}\right)}={10}^1=10\text{W}$$

2. Using mW intermediary:

   $$\begin{gathered} P_{(mW)}={10}^{(40\mathrm{/}10)}=10,000\text{mW} \\ {P}_{(W)}=\frac{10,000}{1000}=10\text{W} \end{gathered}$$

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Quick Reference Conversion Table

dBm	Watts	Typical Application
0 dBm	0.001 W (1 mW)	Bluetooth devices
10 dBm	0.01 W (10 mW)	Small IoT sensors
20 dBm	0.1 W (100 mW)	Wi-Fi routers
30 dBm	1 W	RF transmitters
40 dBm	10 W	Cellular base stations
50 dBm	100 W	Broadcast antennas