Every client asks some version of this question, usually while they're already three weeks past when they should have come in: "how long can I actually stretch between cuts?" The honest answer isn't a fixed number of weeks — it depends almost entirely on the cut you're wearing, not a calendar rule that applies to everyone.
A skin fade grows out the fastest, visually. Because the sides are cut down to almost nothing, even a small amount of regrowth shows up immediately as a fuzzy line where the fade used to be sharp. If you're wearing a tight skin fade, you're realistically looking at every two to three weeks to keep the line clean — anything longer and you're not really wearing a fade anymore, you're wearing the memory of one.
A taper fade or a classic scissor cut is far more forgiving. Because the transition is softer and there's more length overall, you can usually go four to six weeks before it looks like it needs attention. This is the cut most guys underestimate how long they can stretch, and honestly the one where over-cutting (coming in every two weeks for a cut that doesn't need it) is the more common mistake.
Beard maintenance runs on its own separate clock, usually faster than the haircut clock. A beard trim every two to three weeks keeps the shape from drifting, regardless of what your haircut schedule looks like — this is part of why the Beard + Haircut Combo exists, since the two intervals rarely line up perfectly on their own.
The real signal to book, more useful than counting weeks, is when you catch yourself running your hands through it more than usual, or when the line at your neck and sideburns starts looking soft instead of sharp. That's usually a better indicator than any fixed schedule — and if you're not sure, ask your barber directly next time you're in the chair. We'd rather tell you honestly than have you guessing.