Tanner Stage Calculator for Boys

Version 5.3

This is an experimental program attempting to determine your stage of development. The results will only be as accurate as the answers which you give. Do not expect this to substitute for the accurate answers a doctor could give you concerning your development. This tool makes no record of the information given.

In some sections, there might be multiple answers which describe you. If that is the case, select all that describe you.

What does the number mean?

Dr. Tanner divided the time of development into five stages:

  1. Stage 1 is childhood. It lasts from birth until puberty.
  2. Stage 2 begins from the first external signs of puberty until your growth spurt.
  3. Stage 3 is the period when you grow the most quickly.
  4. Stage 4 starts when the rapid growth slows down and ends when you stop growing in height.
  5. Stage 5 is full physical maturity. There are still changes occurring but growth in height has stopped and your body has reached its adult shape.

Details of each stage can be found below. The calculator uses the physical characteristics you report to make the same assessment a doctor would make in determining how far you have developed. Thus, a “2.1” would mean that you just started showing signs of entering adolescence, a “3.5” would mean you are right in the middle of your growth spurt, while a “4.8” would mean that you are just about done physically developing. The scale on the calculator goes from 1.0 to 5.5. It goes above 5.0 to represent the additional development that takes place even after growth in height stops.

Are you curious as to what each stage of development brings? The following pages give a description of the changes which happen in each Tanner stage.


Do you want to know where all of this came from? See Reference Works Used for the Tanner Stage Calculator.