A number 4 haircut uses a #4 clipper guard, which leaves 1/2 inch (13 mm) of hair. Below you can see exactly how long that is, who it suits, the best combinations to ask your barber for, and how often to get it touched up.
| Number | Inches | mm | Scalp shows? | Best for |
|---|
Sizes follow the standard Wahl and Andis guard sets. Some brands differ slightly, so check your clipper’s manual.
What a Number 4 Haircut Looks Like
A #4 gives a longer buzz cut with full coverage. The scalp does not show, and the hair has enough length to show texture and a little direction when you run your hand through it.
Who a #4 Haircut Suits
- Anyone trying a buzz cut for the first time who wants to play it safe
- Fine hair that needs a little length to look full
- Wavy and curly hair, which starts to show its pattern
- Professional settings where a #2 feels too short
Popular #4 Combinations
- All-over #4: a soft, even buzz.
- Crew cut top: #2 on the sides, #4 on top.
- Ivy League start: #3 sides with a #4 top, finished with scissors at the front.
How to Ask Your Barber
Say the guard number and where you want it, for example “#4 all over” or “#2 on the sides, #4 on top”. If you want a smooth blend between two numbers, ask for a half size in between.
How Often to Get It Cut
Every 3 to 4 weeks. It takes about a week to grow to a #5 length. Plan your next appointment with our haircut frequency calculator, and see what it costs near you with our haircut cost calculator.
Frequently Asked Questions
How long is a number 4 haircut?
A #4 guard leaves 1/2 inch, or about 13 mm, of hair.
Can you see your scalp with a number 4?
No, a #4 covers the scalp on most people.
Is a number 4 good for thinning hair?
It can be, because the extra length adds visual density. If thinning is advanced, a shorter #1 or #2 often looks better.
Compare Other Haircut Numbers
Shorter: Number 3 haircut ยท Longer: Number 5 haircut. See every length side by side on our haircut numbers chart.