Why does the calculator say I’m in stage 3 but I haven’t had a growth spurt?

Last updated on August 25, 2020


I took your Tanner Stage Test and it told me I was in stage 3.6. This means I should be in the middle of my growth spurt. However, I have never had a growth spurt, and in the past year, I haven’t grown at all. I answered all the questions accurately, so why am I not growing?!

Thank you.


There can be several reasons, but I don’t enough information to narrow the cause down.

First, until you gain an adult body, you are constantly growing. There are three periods when people grow the fastest: around the time of birth, around the age of five, and in the middle of puberty. During the remaining time of childhood you grow, but at a slow steady rate of about 1 to 2 inches per year. A growth spurt is when the rate of growth increases two to four times faster than before. Therefore, during a growth spurt you can put on two to eight inches in a year. For most boys it is very noticeable, for a few it is less pronounced because it is just a little bit faster than most childhood growth.

Second, it is possible that you haven’t quite reached your growth spurt yet. What I did for the calculator is blend several development scales together. While the order is fairly fixed in any one area, the start and stop times might vary between individuals. For example, you might be developing hair faster than most boys, though other parts of your development might be more typical. I used the multiple scales as an attempt to balance the various aspects of growth out.

The calculator gives more weight to certain characteristics because they are more definitive of the stages or because a person making a self-assessment is less likely to make a mistake selecting the correct stage. But in assigning weights, I could have made a mistake in some area. If you want to send me the answers you put in, I can review it and see if there was an error in the calculations.

Third, the most difficult part of the calculator was coming up with good descriptions of each stage. I’ve never been totally happy with them. What might sound clear to me, might be understood differently by you. Also, since you haven’t reached the point I’m might be describing, it is possible for you to think you are there only to realize a year later that you misunderstood. At least one study stated that boys have a tendency to describe themselves as further developed than they actually are — not intentionally, they just see themselves as more developed than an objective observer would conclude.

I’m not certain how to fix the problem of personal bias and misunderstanding except by exchanging detailed information so I can make corrections if something is off. If anyone reading this wants to help improve the calculator, I would appreciate the help and am willing to work with them.

It is a long explanation, but the summary is if you haven’t had a growth spurt yet, my guess is that you will have one in the next year or so — and probably sooner than later. But that is the closest I can guess at the moment since haven’t seen you. If you are concerned, your doctor can give you a better estimate, both because he can see you and because he can use a bone x-ray to determine more precisely where you are in development.