Graph of the Common Logarithm $y = \log_{10} x$

$y = \log_{10} x$ is the logarithm with base $10$: it gives the power to which $10$ must be raised to obtain $x$. Its domain is $x > 0$ and its range is all real numbers.

Its value increases by $1$ for every tenfold increase in $x$, with $\log_{10} 1 = 0$ and $\log_{10} 10 = 1$. It relates to the natural logarithm by $\log_{10} x = \dfrac{\ln x}{\ln 10}$.