Good afternoon and thank you for posting on the Final Fantasy XIV Technical Support Forums.

As other have mentioned, double-check what resolution scale you have the UI set to. It will give you option for 100%, 150% and 200%. If you have it set to 200% on a 1080p screen, it might look rather large. You can check this setting under the Display Settings in System Configuration.

We hope we can be of assistance in helping you enjoy the exciting world of Final Fantasy XIV!