Logarithmic scale
![A log scale makes it easy to compare values that cover a large range, such as in this map](/Images/godic/202501/24/COB_data_Tsunami_deaths0601.PNG")
![Various scales: lin–lin, lin–log, log–lin, and log–log. Plotted graphs are: y = 10 x (red), y = x (green), y = loge(x) (blue).](/Images/godic/202501/24/Logarithmic_Scales.svg0601.png")
![Plot on log–log scale of equation F(x) = (x−10 )(1020), which can be expressed as the line: log(F(x)) = −10 log(x) + 20.](/Images/godic/202501/24/LogLogPlot_of_Line0601.GIF")
A logarithmic scale is a nonlinear scale used when there is a large range of quantities. Common uses include the earthquake strength, sound loudness, light intensity, and pH of solutions.
It is based on orders of magnitude, rather than a standard linear scale, so each mark on the scale is the previous mark multiplied by a value.