I have 46% frostbite with a hero but I’m not sure how its damage is measured. Is the 46% a chance to cause ice damage? If so how do u know how much damage is ice over physical? 

I am not entirely sure, but I believe the way frostbite works is by converting that specific attack into ice damage with a 46% chance.

@dumpster or @AK47NAPC would certainly have a better answer for you

yes 46%  represents your chance to cause frostbite and its value depends upon your hero’s  Damage value like right now I have two heroes that have frostbite.One is Prometheus(50% )and other is Perseus(46%) so Prometheus does more damage with frostbite he literally kills a phoenix in one strike while Perseus takes two or three strikes at max to kill a phoenix.

You guys are right, 46% of the time the frostbite effect will proc. Same with demolition.