# Logarithmic scale

The logarithmic scale is a nonlinear scale that is used when measurements differ by several orders of magnitude.

Have a look at following three functions plotted on a linear scale on the left and a logarithmic scale on the right. Notice how the exponential function, the first function in the right graph, becomes a straight line on the logarithmic scale.

**Figure 1:** Two graphs with linear x-axes showing three functions, f(x); a positive exponential function (red), a linear function (pale blue), and a negative exponential function (blue). The left graph has a linear y-axis and the right graph has a logarithmic y-axis.

Common uses for a logarithmic scale include earthquake strength, sound loudness, light intensity, growth curves, and pH of solutions.

Check out the logarithmic laws to learn how to calculate with logarithms.