DB ↔ Watts Calculator

Historical Background

Decibel-milliwatts (dBm) is a unit that expresses power relative to a reference value of 1 milliwatt (mW). It is commonly used in telecommunications and audio engineering. The decibel (dB) scale itself is logarithmic, which helps represent wide power ranges more intuitively than linear scales.

Formula

The formula for converting decibel-milliwatts (dBm) to watts is:

\[ W = 10^{\frac{(dBm - 30)}{10}} \]

where:

• \( W \) is the power in watts,
• \( dBm \) is the power level in decibel-milliwatts.

Example Calculation

To illustrate how to convert dBm to watts, consider a power level of 20 dBm.
Using the formula:

\[ W = 10^{\frac{(20 - 30)}{10}} = 10^{-1} = 0.1 \, \text{W} \]

So, a signal of 20 dBm equals 0.1 watts.

Common FAQs

1. What are watts?

   • Watts are a unit of power that measures the rate of energy transfer over time.

2. Why use a logarithmic scale like dBm?

   • The logarithmic dBm scale simplifies comparisons between power levels that differ by orders of magnitude, which often occurs in fields like telecommunications.

3. Is dBm always referenced to 1 milliwatt?

   • Yes, the "m" in dBm stands for milliwatt, meaning the reference is always 1 milliwatt.