It depends on the cut: a skin fade needs 2 to 3 weeks, a taper fade 4 to 6, and a scissor or mod cut 6 to 10. A beard line-up every 2 to 3 weeks keeps you sharp between haircuts.
The honest answer is that it depends entirely on the cut you have, and the gap between a skin fade and a scissor cut is larger than most people expect — two weeks against two months.
How long does a skin fade last?
Two to three weeks before it reads as grown out. A zero guard leaves no length at the bottom, so even a few millimetres of growth closes the gap between the skin and the first length and the gradient disappears.
If you want the look but not the fortnightly visit, a zero fade — clipper-close rather than bare — buys you an extra week or two for the same $38.
How long between taper fades?
Four to six weeks. A taper starting at a 2 or 3 guard has length at the bottom to grow into, so it softens rather than breaking. This is the practical pick if you are not willing to be in a chair every fortnight.
And a scissor cut?
Six to ten weeks. Nothing is cut to the skin, so there is no hard line to lose. A scissor cut or mod cut grows into a longer version of itself rather than into a mess, which is why it suits people who travel or who cannot book reliably.
What about a beard?
A beard line-up every two to three weeks keeps the cheek and neck lines sharp even when you are not getting your hair cut. At $12 for a line-up it is the cheapest way to look like you have just been to the barber.
A simple schedule
Skin fade: every 2 to 3 weeks. Zero fade: every 3 to 4. Taper fade: every 4 to 6. Scissor or mod cut: every 6 to 10. Beard line-up: every 2 to 3, between haircuts.
Booking the next one as you leave is the only reliable way to hold a schedule — every Othman's shop takes the booking at the desk.