I drew it on graph paper so you can kind of see the little squares. Each square represents 6 feet by 6 feet.
The Big area with the letter A is my indoor arena. Standard dressage arena. 66 feet by 197 feet.
I can have 32 stalls (16 on each side) 12X12 stalls.
The slashes are doors.
H- stands for where the hoses will be. I have two.
B- stands for Bathroom.
F/O- stands for Feed and Office area.
T- stands for Tack room. It is 13F by 72F. I want to be able to have at least 32 tack lockers (4F wide 4F deep and 6F tall)
ST- stands for stairs.
I want the loft to cover the whole arena and stalls but not the bottom part. I will store my hay and shavings up here ad well as other things.
The whole dimensions not including the Tack room are 108F wide 221F long and 24,804 square feet (I don't think that includes the Arena)
The people with horses in the stalls at the back will have LONG way to walk to the tack room. Plus half your stalls have no windows, and if you add a loft too the ventilation won't be great. Is there a reason why you wanted your barn this shape?