I’ve figured out stat growth calculating down to mathematical precision that min/maxers love to enjoy.
This is the most important thing to cover right away is how the system deals with the floating decimal that is present in chocobo stats. Your stats will always be displayed rounded down to the closest integer. So, if your chocobo’s stat is displayed at 20, that means it can be anywhere between 20.0-20.8. This becomes very important as everything is done as percentages of the stat maximum.
Because of this floating decimal, people started to think bonus stats might be involved while feeding because certain stats would get more points, making a Grade 1 give +2 or +3 when it should of given +1 or +2. This is simply the floating decimal showing up from time to time. For example, let’s say you have a stat with a stat cap of 260. Your stat would grow like 26.0, 28.6, 31.2, 33.8, 36.4, 39.0. But, the game would display 26, 28, 31, 33, 36, 39; making it look like a bonus showed up from time to time.
This formula took a little crunching to figure out. Your stat caps are determined by (40x((Pedigree-1)+Star Rating))+20. So, your starting chocobo is Pedigree 1 (P1) and has 2 Star Ratings in all stats, so all stat caps are 100. If a P2 Chocobo has all stats at 2 Stars, all stat caps are 140. The maximum stat caps are 500 with a P9 Chocobo with all 4 Stars.
When your chocobo is Rank 1, it’ll have 11% of the stat cap. (Note: The starting percentage might vary based on pedigree, everyone started keeping track at P2) So, if your Chocobo’s stat caps are 180/180/140/180/220, your starting stats will be 19/19/15/19/24 because of the floating decimal. That means, you have 445 total percent (or let’s call them points to make it simple) to gain before being completely maxed out.
Each rank, you gain 5 percent points that are spread randomly between all the stats. That means you’ll either see 5 different stats go up by 1%, or you might see 3 stats go up by 1% and 1 stat go up by 2%, or 1 stat go up by 1% and 2 stats go up by 2%. I’ve yet to see data of 1 stat going up by 3% from ranking up, but it is possible depending on RNG. That means, going sololy off of gaining points through Ranking up, it’d take you until Rank 90 to hit max assuming stats spread in a perfect manor.
Rank 90 is a LOT of racing to achieve max stats, so this is where feeding comes into play. Grade 1 food raises a stat by 1%, Grade 2 is 2%, etc. So, when we add food into the formula, the Rank required starts to fall quickly.
Assuming using only Grade 1 food, you can achieve max stats at Rank 76. Using Grade 2 food, Rank 65. And using only Grade 3 food, max stats are achieved at Rank 57. The maximum Rank is 50 at which point, your chocobo stops gaining XP. So, it seems it is impossible to achieve 100% maximum stats at this time.
Since points from Ranking up seem to be completely random, when trying to go for a maximum stat Chocobo, it’ll probably be best to stop feeding around Rank 40, and letting points from Ranks fall where they will. You should NEVER feed up to maximum in one stat as you could easily start wasting points. This is completely dependant on how the RNG system works and if it’ll keep trying to apply points to a stat that can no longer go any higher, of course. But to play it safe for now, I’d avoid feeding past 80% of stat cap. This is recommended, not fact.
Grade 1 food is the easiest. You can buy it from the Feathervendor in Bentbranch for 1500 gil. You can craft this food yourself, but the materials are extremely expensive and it is impossible to get HQ Feed. So, just buy your Grade 1s. Personally, that’s all you should need for your first few chocobos.
Grade 2 food has multiple ways to acquire. The easiest is buying it from the vendor in Gold Saucer for 1100 MGP. If you want to try to stockpile as much Grade 2 as you can, you can easily buy the food as soon as you have more then 1100 MGP, then pay gil to get back up to 500 MGP, making it so you only have to earn 600 MGP per food (and roughly 5k gil).
Grade 2s can also be crafted. It is a 2* CUL recipe, but since HQ is impossible, you don’t need any melds to craft this feed. You can simply use food to boost your crafting stats high enough to craft all the feed you need. The materials for this feed are from 1* MIN/BTN nodes located in Eastern Thanalan. The MIN node is at 9 AM, and the BTN node is at 1 PM. You can only get one mat from each node per Eorzean day, you can hit both nodes in the same day. You will also need the higher-level chocobo feed that can only be acquired through cross-breeding plants, each feed uses a different plant. FFXIV Gardening is an excellent resource for all of your gardening questions.
Grade 3 food can only be acquired through the vendor, costing 2750 MGP each. Start stocking up now if you intend on using Grade 3s.
I’m going to answer this here because it seems to be the most common question. ‘Do I need to feed my chocobo if I’m just planning on breeding it?’
No. Feeding is 100% optional, however, feeding means you’ll have higher stats for racing which means more victories, YAY! Choosing not to feed will save you gil and MGP, but require you to run more races to reach Rank 40. But again, feeding is 100% optional if you’re only worried about breeding.