A scale that uses distances on a graph to represent ratios. For example, the ratio between 3 and 6, and between 6 and 12, is the same (the larger number is twice the smaller number). In a ratio scale chart, all changes by the same ratio are represented by the same vertical distance. This contrasts with a linear scale, where the distance between 3 and 6, and between 6 and 9, is the same (in this case, 3). Also known as a log scale (in for example, Microsoft Excel).