Hit Probability Calculator

About this calculator

In tabletop and video game combat systems, the chance that an attack lands is usually modeled as the attacker’s accuracy stat working against the defender’s evasion stat, with the raw difference converted into a probability and then clamped between a floor and a cap — for instance never letting hit chance drop below 5% or exceed 95% — so that even heavily mismatched characters retain some chance of a hit or a miss, keeping outcomes unpredictable rather than deterministic.

Game designers tune these floors, caps and the accuracy-versus-evasion curve during balancing passes to control how punishing high evasion builds feel and how reliable high-accuracy builds are, since a formula with no clamping can make some matchups feel either guaranteed or hopeless. Enter your accuracy and the target’s evasion to see the resulting hit chance.