How to Label Semi-log Graph Paper


Over the past several years, it has become clear that not many students know how to label and use semi-log graph paper. There is no real trick to it. The only thing that you need remember is that the log axis runs in exponential cycles. Each cycle runs linearly in 10's but the increase from one cycle to another is an increase by a factor of 10. So within a cycle you would have a series of: 10, 20, 30, 40, 50, 60, 70, 80, 90, 100 (this could also be 1-10, or 0.1-1, etc.). The next cycle actually begins with 100 and progresses as 200, 300, 400, 500, 600, 700, 800, 900, 1000. The cycle after that would be 1000, 2000, 3000, 4000, 5000, 6000, 7000, 8000, 9000, 10000. Below is a picture of semi-log graph paper with 6 cycles on the x-axis.

6 Cycle

The next sheet of paper was an attempt to show you how the progressions worked. Unfortunately, I could not physically fit all of the numbers on the graph. So I have provided some of the numbers. Try to fill in the rest of numbers by continuing what I have started.

Log Axis Labels

An alternative to using semi-log graph paper is to use linear paper. Instead of plotting your linear data vs. the exponential data you would acutally take the log of the exponential data then plot it.

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