How long
How many days do you need in Naxos?
Four to five days cover the island itself. Eight let you add the Small Cyclades without rushing. The difference is not one of pace: they are two different trips.
Four to five days: the island
Chora and its Kastro, the west-coast beaches, the inland villages, and the climb up Mount Zas — the highest point in the Cyclades — from Filoti. That is complete, and it is already a lot.
8 days: the island and the archipelago
The same, plus a crossing to the Small Cyclades. It is the length the guide's route is built around, and not by accident: below it, the crossing turns the trip into a sprint.
If Greece is getting ten to fourteen days
Using Naxos as a single base for five or six of them means unpacking once instead of every other morning. It is also the island best placed for it: it is the ferry hub for the Small Cyclades, and it works without a car.
What this page does not tell you
These lengths assume independent travel outside the August peak. In July and August, crowds and booking pressure change the equation: allow more margin on both transport and accommodation.