Crit % with spells addon?

[nemof]

I am looking for an addon that adds information about my spell crit%, like caster stats:
http://www.curse-gaming.com/en/wow/a...ter-stats.html

however caster stats seems to no longer work as it is not being maintained.

if there are no such addons, does anyone know the formula to calculate your chance to crit with spells based on your INT bonus and level?