xivgear.app is a brand-new FFXIV gear set builder, that avoids the need to copy sets into a separate spreadsheet/calculator to check their expected DPS, or to quickly compare them side-by-side.
Here's a few of the features it supports:
For some classes, DPS simulations built right into the gear set editor, for instant feedback.
Share a sheet containing multiple sets, so players can view them at a glance, rather than having to click through several sets.
Set a stat priority and have materia automatically chosen for you.
Coming later: leave a few slots empty, and brute-force solve the highest DPS sets.
Happy Raiding! Don't forget to check out The Balance for best-in-slot gear sets.