#### Unit power

\[ P_{\text{dBm}} = 10 \times \log_{10}(P_{\text{W}} \times 1000) \]

\[ P_{\text{W}} = \frac{10^{\frac{P_{\text{dBm}}}{10}}}{1000} \]

#### Unit distance

\[ 1 \text{ mil} = 0.0254 \text{ mm} \]

\[ 1 \text{ mil} = 0.001 \text{ inch} \]

\[ 1 \text{ inch} = 25.4 \text{ mm} \]

#### Unit ratio

\[ \text{Voltage ratio: } \text{dB} = 20 \times \log_{10}\left(\frac{V_2}{V_1}\right) \]

\[ \text{Current ratio: } \text{dB} = 20 \times \log_{10}\left(\frac{I_2}{I_1}\right) \]

\[ \text{Power ratio: } \text{dB} = 10 \times \log_{10}\left(\frac{P_2}{P_1}\right) \]