Tracking and Rotoing time estimate

Just wondering how you guys measure the amount a shot will take to complete.
I have a huge lot of shots from easy shots with no rotoing and min tracking to lengthy shots with lots of rotoing and tracking. How do you guy manage this? Is there a rule or chart you have that will help with this?

Thanks,

This is not something easily calculable, it depends on your skill level and familiarity. A fast paint shot takes an hour, a hard one might take a whole day or two. Similarly, rotoscoping buildings, boats, and rigid surfaces may take a few hours, tops, while rotoscoping dancing humans can take significantly longer.

Base this off of your experiences with shots, it will not be the same across the board.