couldn't you just see how many chins and experience you get in 15mins of chinning? then take your current exp of 99 exp then divide that by the amount of experience you received from those 15mins then use that number to multiply by the amount of chins you used in the 15mins? i.e : (bare in mind i know these numbers are not accurate, i've never chinned before so i have no idea of experience etc etc. 15 mins of chinning say gained 50k exp and you used 200 chins also presume the amount of exp remaining to 99 was 3million 3,000,000 / 50,000 = 60 thus 60 * 200 = 12000 so 12000 chins for 3,000,000 experience. I KNOW THESE NUMBERS ARE NOT ACCURATE but i believe the use of this equation : ((EXP To 99) / (EXP Gained within allotted time)) *(chins used in allotted time) = number of chins i HAVE, without a doubt, gone wrong somewhere me thinks. but maybe not ;) i tried :)