I've created an online Chocobo Raising statistics calculator

http://jamesdonnelly.github.io/xiv-chocobo-raising/

Screenshot: http://i.imgur.com/o8IrKh3.png

It takes a Chocobo's Rank and Exp. and calculates the equivalent of how close you are to your next Rank, Rank 10, 15 and 20 respectively. It looks at:

1. How much experience is required, and how much experience your Chocobo has gained overall;
2. How many times your Chocobo could have been trained in a Stable since you first unlocked it, and how many more times it'd need to be trained;
3. How many times you could have completed the weekly Challenge Log entries thus far, and how many more times you'd need to do that.

My Chocobo is Rank 11 with about 1.1M experience. If I plug that in it'll tell me that she can be trained 43 more times or that I can complete 3 more weeks' worth of Challenge Log entries to rank up. If I train her 446 more times she'll be Rank 15. If I complete 57 more weeks' worth of Challenge entries she'll be Rank 20.