The armory chest is 25 for a single equipment slot and there are 13 unique slots/tabs if I'm not mistaken.
There's 4 tabs of inventory for consumables/craft items/selling drops.
Another Key Item (quest items) tab.
Crystals also have their own inventory tab.
Assuming I'm remembering the layouts correctly that's 450 + crystals (I haven't paid attention to this tab tbh). Also that's all out in the field accessible.
There may also still be the retainer system from 1.0 which would be another 150 slots. Also the Armoire from the Inns. I haven't checked if either of these is available in ARR I just read about them when I first flipped out about how awesome the inventory system in 14 seems.