Because the Growth Gene, and the way of figuring it all out, is one beast of a topic, it deserves its own guide.

I’ve also partnered with Gathouria, who - using the math on my Genetics guide and a little calculator I made in Sheets - has really refined the prediction process of the Growth Gene, and made a much better looking calculator that Gath has generously made public.

Calculator Quick Link
Stats Charts Quick Link

What is the Growth Gene?
The Growth Gene determines how much a not-cat‘s stats and weight increase at each stage of their life. There are nine different Growth Genes, which influence your not-cats growth in unique patterns as shown below.


From this, I figured out a basic way of predicting what stats an adult not-cat could get. From one growth stage you could figure out the minimum and maximum stats your not-cat could get. But from two or more growth stages you could figure out more accurate adult stats, as well as the growth gene itself. It is based on the math below.

A|A = Very Early _______ A|B = Early _________ A|C = Decreasing
B|A = Arch _____________ B|B = Steady _______ B|C = Dip
C|C = Increasing _______ C|B = Late __________C|A = Very Late

The basic idea is that you fill in all the equations, and then find the pattern where the results are the closest (usually within a +-5 margin).

I had made a quick and dirty calculator to do this all in seconds, which I then gave to Gathouria, who then refined it and made it look nice. After giving Gath the basics for a weight calculator, Gath figured out how to more accurately predict the growth gene, and therefore more accurately figure out adult stats and weight.

And so, here is Gathouria to explain exactly how it all works.

Please bear in mind that this is a Collab effort, I began with the math and a rough calculator, Gath refined it and discovered the importance of weight being accurate. It’s not Dark’s calculator nor is it Gath’s calculator, it’s Dark/Gath and Gath/Dark’s calculator

Calculating with Stats vs. Calculating with Weights

So the growth pattern of a not-cat influences not only their stats at every life stage, but also their weights at every life stage.

While stats are the more useful and visible numbers, using them in math to determine growth patterns produces higher margins of error for the following reasons:

• At any given stage, a stat's value, if it has a decimal of any kind, will be rounded up. The rounded numbers are the only values that will be visible to you.
  
• There are limitless combinations of final stat totals of every stat.
  

Weight gets around these issues in that:

• The weight of non-adult not-cats can have decimal values and are thus precise.
  
• Adult not-cats do not have decimal values in their final weights (in lbs.), giving us a limited number of final values.
  
• Bonus: This math can be done with Beans, who do not have visible stats values.

We can take advantage of these facts about weight to get really accurate calculations for growth pattern that can then be applied to the stats, the values you probably care about!

Due to the discrete numbers of final adult weights and the precision younger weights allow, given enough data points (as few as just two, and sometimes just one) we also can be 100% certain of the growth pattern with no margin of error.

Let's look at the calculator that makes this easy!

Growth Pattern via Weight Calculating

Let's run through an example using one of my not-cats that I have information for from a young age: Daisycloud


Here's her info as I recorded it while she was growing up:
Keep in mind for now that these were from before we had Students, but those will be addressed later.


The quickest way to get a growth pattern is to plug in the weights. I'll be using this handy dandy calculator to make things easy. We'll be looking at the Whole Number Check tab, which does math that takes advantage of the whole "no decimals in adult weights" thing.

Here's what it should look like once you've entered the info we have in to the yellow boxes. The name spot is optional and just for linking screenshots to the cat they're for.



We're looking for a row that highlights entirely in green and that has all the same number. For Daisycloud, that's the B|A row. That means that she has a B|A (Arch) growth pattern and will weigh 9 lbs. as an adult. That means we're lucky- no more info needed for determining the growth pattern! (more complex cases will be addressed at the end of this post)

Next let's look at what to do with our new-found knowledge.


Determining Adult Stats

Now, for what you probably care about- your not-cat's adult stats.

We'll switch over to the Single Age Calculator tab for this one.

Plug in the growth pattern from before and pick an age you have stat data for (the closest one to adult age is usually the most precise). Here's what it should look like:



That Adult Stat Ranges section is what we're looking for. That's your not-cat's adult stats. And we're done!


Incorporating Multiple Ages

Right now, you can compare the predicted adult ranges by plugging in different ages and seeing what numbers overlap in order to get a more accurate prediction. I hope to have the calculator do this for you in the future.


Student Stat Gains

Students make the calculations a bit more complicated, but not by as much as you might think!

When a Student gains a stat to their final adult value, their current stats will actually update to reflect what the new adult number will be.

This means:

• If the Student's number for that stat CHANGES after an increase...
  ...then their adult stat will be the highest previous prediction PLUS one
  
  e.g. If a Student had a FIN stat of 12 before a finesse increase and that stat is now 13,
  ...and the adult prediction before they increased was 16-18,
  ...that means their adult FIN stat will be 18 + 1 = 19
  
  
• If the Student's number for that stat STAYS THE SAME after an increase...
  ...then their adult stat's predicted minimum increases by one
  
  e.g. If a Student had a FIN stat of 12 before a finesse increase and that stat is still 12,
  ...and the adult prediction before they increased was 16-18,
  ...then the new predicted range is 17-18

More Complex Cases

The example I gave above gave us a single potential answer using just two weights. That isn't always the case.

Complications can include:

• Multiple potential adult weights
  
  Sometimes the calculator will show you two fully viable adult weights. That means the kitten could have either as an adult, and as a consequence, any growth pattern associated with those rows.
  
  This is fairly common for cats with only a single weight value recorded. You will need more weight values to fully determine the growth pattern.
  
  
• Bugged young cat weights
  
  Prior to July 2022, there was a bug that caused young not-cats to display the wrong weights. If your data is very old, then it's possible you can't use that weight data.
  
  In this case, try plugging in stat totals into the Stat Total Calculator tab and looking to the colorful column to the right for the smallest numbers. Those will be the most likely growth patterns.
  

Additional Tips and Tricks

• An adult cat's weight can be a minimum of 4 lbs. and a maximum of 24 lbs.
  
  If any numbers are highlighted that are higher or lower than this, then you can rule out those associated growth patterns- they're not possible.
  
  
• For cats that have biological parents
  
  A kitten's final adult weight will be any number between and including the adult weights of their biological parents. This can be used to rule out some potential weights shown on the calculator, and thus their associated potential growth patterns.
  
  
• For cats that have biological parents with known growth patterns
  
  Knowing the growth pattern of even just one of the parents will help you narrow it down even further, letting you eliminate impossible inheritance patterns.
  
  North parents will give either of their genes to the first slot, South to the second, Trade to either. (A full guide on genetic patterns can be found here and a full guide on breeding and inheritance here)
  

Conclusion
Weight values are a much more accurate means of determining growth patterns, if that data is available to you. You can still do these calculations with just stat values, but there will be a larger potential margin of error, as these numbers aren't precise. Use all the records you have available to you and you'll have a perfect prediction in your hands.

Just make sure to have your calculator handy!

If you are confused on how to use your data, feel free to send me a message and I'll help you get your data sorted!
Go have fun with genetics, everyone!

After putting it off for a long time, because I dreaded doing all the math, I have made a cheat sheet of growth stats.

I needn’t have worried about doing all the math because I made myself a mini calculator to help. Boredom breeds innovation.

The chart pictured below groups the stats into their growth stages, and then into growth genes, with any genes that have the same result being grouped further.

Gathouria has added this to the sheet as a new “Single Age Calculator”

To use this chart manually, you will still need to use the “Whole Number Calculator” to find the growth pattern of your not-cat. However, once you know the growth pattern, you can match it to a cell in the Colourful Growth Pattern box, and then look at the stat ranges in the three charts.

For example, if I have a Young Kitten with AB growth, I match it to the Yellow pattern, and look at the Yellow columns in the Young Kitten chart.
A Kitten with CA would be the Red columns in the Kitten chart, and an Adolescent with BA would be the Green columns in the Adolescent Chart.

Once you know which columns you’re looking at, you check your not-cats current stats (left), and match them to the range of adult stats they could have (right).

As you can see, the range from red to green goes from largest range to smallest range, with the red patterns having the widest range of possible adult stats, and the green patterns having the narrowest. This explains the variety of inaccuracies that can be founded when using the stat calculator (above).

As well, as a not-cat ages, the stat ranges shrink, leading to a more accurate prediction of adult stats.



I hope this helps give a better understanding of how stats work, as well as giving a more accurate representation of any adult stat predictions.

The growth calculator and the guide have been updated to reflect a new, easier method for determining growth patterns and to incorporate Dark's chart information!

Sorry to interrupt, but the backward stats calc is broken and legendary status is purple so I would like to share an edited copy
Edited

@Cheeksstripe whoops, I haven't used that tab in so long that I didn't notice didn't realize anyone used it but myself and maybe 1-2 others! I've rolled back the version to before the break (that kind of break seems to happen when cells are accidentally dragged and is hard for me to prevent from happening while allowing others to edit). Permissions have also been corrected to allow editing Adolescent.

I've also changed the legendary color to pink! Thank you for pointing that out, those colors were selected so long ago. I've chosen red, purpley-blue, and a yellowy-green color for the growth colors rather than red/blue/orange, for hopefully more visual contrast for visual impairments and blue light-filtered screens

@gathouria
The exceptional status is supposed to be purple

@Cheeksstripe whoops, looks like I changed that part by accident Those two stat boundaries should now be distinct colors again. Thank you for pointing that out