How to convert block rating to block chance

I wanted to work out how much block the RR100 shields would provide (potentially saving me renown points on block rating) so I worked it out quickly. It's probably already posted on Warhammer Alliance or on another blog somewhere but meh... was too lazy to look for it and brain needed a work out.

10 block rating on a shield = a 0.57% chance to block

This is a rough number but it works out pretty much dead on what block chance you get.

Tactics, Renown and +block% items add on after the block rating is worked out, so a 500 block rating shield with +2% block bonus would give you a base block chance of 30.5%. If you had a +10% block tactic on that would then give you 40.5% block.

Edit: Thank you to Anonymous who posted the following in the comments. It's the actual formula and gives you the exact block rate, even if it is a bit more numbery

The calculation works for characters that are level 40, as the equation factors in level per block rating.

Block Rating / (((Level * 7.5)+50)*5) = Block(*100) = %

So for example, at level 40 this works out to be Block Rating/1750.