Gain-dB Converter

Convert between ratio gain $G$ and decibels $\mathrm{dB}$ using amplitude or power conventions. Amplitude mode uses $\mathrm{dB}=20,\log_{10}(G)$; Power mode uses $\mathrm{dB}=10,\log_{10}(G)$. Type in either input to update the other and the result. The plot and reference table track your selection; select Extend Plot Range to view a wider span.

Formula

Convert between ratio gain G and decibels (choose mode):

Amplitude (voltage, current):

$$\mathrm{dB} = 20\,\log_{10}(G),\quad G = 10^{\mathrm{dB}/20}$$

Power (ratios of power):

$$\mathrm{dB} = 10\,\log_{10}(G),\quad G = 10^{\mathrm{dB}/10}$$

Converter
?
Type in either box — the other updates automatically.
Result Enter a gain or dB value.
Reference Table
Common dB values and corresponding gain:
dB Gain (Amplitude)
Plot