I made a desmos calculator to determine the amount of damage and %resistance reduced by armor pierce, with power added as well for comparison.

Some useful information:

- At the current level cap (140), the opponent needs to be using 3350 def (not HP, def) for armor pierce to be equivalent to power.
- However, at level 350, assuming the target ran 1.3k def at level 140 and didn’t change their gear (they’ll have roughly 3.3k def at 350), armor pierce will be equivalent or better to power. That is, the higher the level, the better armor pierce is due to the way it scales.
- At 50% armor pierce (190 AP), you do an additional 27% damage through blocking.
- This tool is meant for PvP calculations only. PvE armor pierce uses a different formula, which is much simpler: 1/2 your AP % is the additional damage% against npcs