Calculator For Opposed Checks?

[Gale]

Sometimes I'm curious what the odds are of a character winning an opposed check against another creature, but I have no idea how to begin figuring it out.

Like today, I wanted to see what the chances were of winning a contested grapple check when Creature A has advantage, bardic inspiration (+1d8), and a +8 Athletics, while Creature B only has a +4 Athletics. I know the odds are ridiculously in favor of Creature A, but I have no idea what the actual chances are.

Is there a calculator for figuring these kinds of things out? Or at least a formula that's relatively easy to follow?

[JNAProductions]

Anydice (https://anydice.com/)to the rescue!

Your specific question is this program here (https://anydice.com/program/243ab). And it's a just over 81% chance of success on the +8+1d8 versus +4, assuming you need to BEAT the enemy's roll, not just match.

[Gale]

Anydice always confused me admittedly, but this is really useful. I'll definitely try and learn a bit of it, if only for figuring stuff like this out.

Thanks~!