Sizu Home › Calculators › Read a Log Axis
Opens on Chapter 10’s example: the app that grew from 1,000 to 64,000 users in six months.
Placing a value
Growth
Enter your numbers, then press Calculate.
How it works
Halfway between two gridlines on a log axis is √(lower × upper), not their average. A value sits log(value ÷ lower) ÷ log(upper ÷ lower) of the way up the gap. Growth from start to end over n periods is (end ÷ start)^(1 ÷ n) per period; the number of doublings is log₂(end ÷ start).
From the book, Chapter 10. Halfway from 10 to 100 is 31.6, and 50 sits 70% of the way up. 1,000 to 64,000 is 6 doublings: twice a month. Slowing to 10% a month for six months still takes 64,000 to 113,380, up 77%. Every chapter and its calculator →
Rounding is half up, the way the book rounds. Numbers can be typed as 1,450, $38, 12% or 2.5 million. Everything stays in your browser: no sign-up, nothing stored or sent.