Quick answer On most clippers, each guard number adds about 1/8 inch: a #1 leaves roughly 1/8 inch (3 mm), a #2 1/4 inch (6 mm), and a #8 about 1 inch. Start one guard longer than your goal, cut against the grain, then work down.
Ask for ‘a 2 on the sides’ and a barber knows exactly what you mean. Open a set of clipper guards at home, though, and the numbers stamped on the plastic can feel like a code, one where a single wrong size is the difference between a sharp buzz and a stripe of scalp. The system is simple once you see the pattern: on most clippers, each number adds about an eighth of an inch.
Below you’ll find the full #0 to #8 chart in inches and millimeters, which number suits a buzz cut, crew cut, taper, fade or beard, and how to blend a basic fade at home by working from the longest guard to the shortest. You’ll also pick up the rule barbers live by: when in doubt, go one number longer. You can always take more off, but you can’t put it back.
Time 30-60 minutesDifficulty BeginnerSteps 9
Clipper Guard Sizes Chart
| Guard | Length (in) | Length (mm) | Typical use |
|---|---|---|---|
| #0 (no guard) | Under 1/8 in | Under 3 mm | Fade base, neckline |
| #1 | 1/8 in | 3 mm | Short buzz, heavy stubble |
| #2 | 1/4 in | 6 mm | Classic buzz, fade band |
| #3 | 3/8 in | 10 mm | Classic buzz, crew sides |
| #4 | 1/2 in | 13 mm | Soft buzz, short beard |
| #5 | 5/8 in | 16 mm | Crew top, fuller beard |
| #6 / #7 | 3/4 / 7/8 in | 19 / 22 mm | Fuller beard |
| #8 | 1 in | 25 mm | Longest guard, fuller beard |
What You’ll Need
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- Cordless hair clipper with a full guard set, #0.5 to #8 The clipper and its numbered guards set every length in this guide, and one matched set keeps the sizes consistent.
- Barber cape Optional: keeps clippings off your clothes and out of your collar while you cut.
- Handheld mirror Held up to a wall mirror, it lets you check the back, the crown and the neckline you can’t see head-on.
- Fine-tooth barber comb Lifts a longer top out of the way and lets you check that each band lies even before you move to the next guard.
- Sectioning clips Optional: only needed if the top is longer than you plan to clip, to keep it away from the guard.
- Clipper blade oil and cleaning brush A clean, oiled blade cuts without pulling. Some clipper kits include both, so check the box list before you buy.
- Cordless detail trimmer Optional: gives a crisper outline around the ears, sideburns, neckline and beard line than a full-size clipper blade.
Step-by-Step
Step 1 Check your clipper’s own size chart
Before you cut, match every guard in your set to the length it actually leaves. On the standard numbering most home kits follow, a #1 leaves about 1/8 inch (3 mm) and a #2 about 1/4 inch (6 mm), and each number after that adds roughly another eighth: #3 is 3/8 inch (10 mm), #4 is 1/2 inch (13 mm), #5 is 5/8 inch (16 mm), #6 is 3/4 inch (19 mm), #7 is 7/8 inch (22 mm) and #8 is about 1 inch (25 mm).
The lower the number, the shorter the cut.
Half sizes fill the gaps a fade needs: a #0.5 is about 1/16 inch (1.5 mm) and a #1.5 about 3/16 inch (4.5 mm). A #0 means the bare blade with no guard, which cuts shorter than a #1; exactly how short depends on the blade and the lever position.
Charts agree on the #1 and #2 anchors but drift on the higher guards, and some brands, Oster among them, number their attachments on their own scale (a ‘number 1’ detachable blade is not the same length as a #1 guard). Trust the length printed on the guard or the chart in your box over the number, and never mix guards from two brands mid-cut.
Step 2 Match the number to your style
Pick the look first, because it decides which guards you need. A buzz cut is one guard all over: a #1 reads very short, a #2 or #3 is the classic, and a #4 gives a softer buzz with more coverage over the scalp.
A crew cut keeps the sides at a #2 or #3 under a longer top at a #4 to #6. A taper shortens only the hairline at the sideburns and nape, from a #3 down to a #1 for example, and the same short guards, a #1 or #2, cut a nape or side undercut beneath longer hair.
Fades use a ladder such as #0, #1, #2 and #3.
What separates a low, mid and high fade is where the shortest band stops: just above the ear, around the temples, or up near the widest part of the head. Beards use the same numbering: a #1 for heavy stubble, #2 to #4 for a short, neat beard and #5 to #8 for a fuller one.
Step 3 Set up on clean, dry hair
Clip only clean hair that is completely dry and free of styling product, because damp or coated strands clump inside the guard, drag and cut unevenly. Put on a barber cape, sit facing a large mirror and keep a hand mirror within reach so you can check the back.
If the top is longer than you plan to clip, comb it up and hold it out of the way with sectioning clips so the guard can’t catch it.
Then brush any old hair out of the blade with the cleaning brush, add a drop of blade oil and snap the guard on until it clicks. A guard that pops off mid-pass is the fastest way to a bald patch.
Step 4 Start one guard longer than your goal
Make your first pass one size longer than the length you want, for example a #3 if you’re aiming for a #2. A guard can only take hair off, so starting long gives you a safe, even base and a chance to judge the result in the mirror before you commit.
Work the clipper up the head from the hairline with the guard flat against the scalp, overlapping each stripe by about half its width so no tufts are left behind.
If the length looks right, stop there. If not, switch to your target guard and go over the whole area again: going shorter is always easy, and going back is impossible.
Step 5 Cut against the grain for closeness
Clipper direction changes the result as much as the guard number does. Moving against the grain, opposite to the way the hair grows, lifts each hair into the blade so you get the full, close length the guard is rated for.
On the sides and back, hair mostly grows downward, so against the grain usually means moving upward. Going with the grain lets hair lie flat under the guard and leaves it slightly longer and softer.
That makes it the safer choice for a nervous first pass, for the crown where hair grows in a swirl, and for beards on skin prone to irritation or ingrown hairs. To find the growth direction, run your palm over the area: the way the hair lies smooth is with the grain.
Step 6 Blend a simple fade down the guards
For a basic low fade, cut the sides and back with your longest side guard, say a #3, up to the widest part of the head, where the sides turn into the top. Switch to a #2 and stop about an inch lower, take a #1 to just above the ears, then finish with a #0.5 or the bare blade around the ears and along the neckline.
For a mid or high fade, raise every stop line. Working from long to short means each shorter guard only touches hair below the last line, so the length steps down gradually.
As each guard reaches the top of its band, flick the clipper outward, away from the head, so the shorter length feathers into the longer one instead of leaving a shelf. If a line still shows between two bands, go over it with the half size, or open the clipper’s lever on the shorter guard, which lengthens the cut slightly and softens the step.
Step 7 Clean up the neckline and edges
Once the fade is blended, tidy the outline so the cut looks finished. Use a detail trimmer without a guard, or the clipper’s bare blade, to define the edges around the ears and sideburns, and check both sideburns in the front mirror at once to keep them even.
At the nape, choose between a natural, tapered neckline faded with a #1 or #0.5, which grows out softly, and a squared or rounded line, which looks sharper but shows regrowth sooner because new hair appears below a hard edge.
Check the back by holding the hand mirror up to your wall mirror, and trim only the stray hairs below the line rather than pushing it higher.
Step 8 Fix mistakes one guard longer
If a band looks too short or a patch dips below the rest, don’t chase it with a shorter guard, because that only spreads the problem. Take the guard one size longer than the one that slipped and blend the hair around the spot, so the short patch becomes the bottom of a gradual step instead of a hole.
A visible line between two lengths gets the same treatment: work the half size or the opened lever over it until it softens. Whatever is left fades quickly from view, because even a week or two of regrowth at about half an inch a month softens a short patch noticeably.
Step 9 Clean the blades and log your numbers
When you’re done, brush the hair out of the blade and guards with the cleaning brush, add a drop or two of blade oil and run the clipper for a few seconds to spread it. Clean, oiled blades cut without pulling and stay sharp longer.
Wipe off the excess oil before you store the clipper. Then write down exactly what you used: each guard number, where each band stopped and whether the lever was open or closed. That note is what makes your next cut match this one, and it’s the same shorthand a barber understands.
Common Mistakes to Avoid
- Starting with the guard you want, or a shorter one, instead of one size longer, which leaves no safe way back if the result is too short.
- Assuming a #2 is the same length on every brand, or swapping in guards from a different set halfway through the cut.
- Not snapping the guard on until it clicks, so it slips off mid-pass and leaves a bare patch.
- Stopping every guard at the same height, which cuts a hard line instead of a gradual fade.
- Clipping damp or product-coated hair, which clogs the guard and leaves the length uneven.
Pro tip Check your blend under one strong light from above or the side, not soft, even bathroom light. Directional light casts a shadow into any step between two guards, so you’ll spot the line that needs softening before anyone else does.
The Bottom Line
Clipper guard sizes stop feeling like a code once you see the pattern: on most clippers each number adds about an eighth of an inch, and lower always means shorter.
Pick the numbers for your style, start one guard longer than your goal, cut against the grain for a close result and step down the guards for a fade. Keep your written numbers, and a re-cut every two to four weeks will look the same each time.
Book a barber for a skin fade, a razor-sharp line-up or a shaved part, or when a slip has left a patch you can’t blend. A pro can often reshape the whole cut around it. Bring your numbers along, because they’re the fastest way to get exactly the cut you have in mind.
Frequently Asked Questions
What number clipper guard should I use for a buzz cut?
A #2 (about 1/4 inch, 6 mm) or #3 (3/8 inch, 10 mm) all over is the classic buzz cut. A #1 (1/8 inch, 3 mm) reads very short and shows more scalp, while a #4 (1/2 inch, 13 mm) gives a softer buzz. If you're unsure, start with a #4 and work down one size at a time.
How do I ask a barber for a haircut using clipper numbers?
Name the guard for each zone and where it changes, for example: 'a #3 on the sides, a low fade down to a #0.5 at the neckline, and about two inches left on top.' If you're unsure of a number, ask for one size longer than you think, because a barber can always take more off. A photo plus the numbers works best.
Is a higher or lower clipper guard number shorter?
Lower is shorter. A #0 is the bare blade with no guard, a #1 leaves about 1/8 inch (3 mm), and each number up adds roughly another eighth of an inch, reaching about 1 inch (25 mm) on a #8. The exception is detachable pro blades, which use their own numbering, so check the length marked on your attachment.
How often should I re-cut a fade or buzz cut?
Hair grows about half an inch a month, so two weeks adds about 1/4 inch, the length of a #2 guard. That's why fades lose their crisp gradient first, usually within two to three weeks, while an even buzz holds its shape longer, often three to four weeks. Tidying the neckline between full cuts stretches the look.
Can I use clipper guards to trim a beard?
Yes. Beard trimming uses the same guard numbering, so choose the size by the length you want: a #1 for heavy stubble, #2 to #4 for a short, neat beard, and #5 to #8 for a fuller one. Trim with the grain on the neck and cheeks if your skin is prone to irritation, and use a detail trimmer for the neckline.
Keep Reading
Sources
- Haircut number system styleseat.com
- Haircut numbers latest-hairstyles.com
- What clipper guard size should i be using to trim my beard dollarshaveclub.com
