Clipper Guard Sizes:
mm to Guard Number Chart

What Is Each Clipper Guard Size in mm?

Clipper guard sizes convert at roughly 3 mm per number: a #1 is 3 mm, #2 is 6 mm, #3 is 10 mm, #4 is 13 mm, #6 is 19 mm and #8 is 25 mm. Half sizes sit in between, so a #1.5 is 4.5 mm, and a bare blade cuts to about 0.5 mm.

The same millimetre lengths apply to beard trimmers; the stubble beard settings guide matches each length to the look it gives.

Source for guard numbers and inch sizes: Guide to hair clipper guard sizes, Wahl USA. Millimetre values are the inch sizes converted and rounded.

Do Half-Size Guards and the Taper Lever Change the mm Length?

• Half sizes (#0.5, #1.5, #2.5, #3.5) aren't included with every clipper set but are sold separately. They're what barbers use for smooth fades.
• Metric clippers are usually labelled directly in mm, so use the right-hand column.
• The taper lever on most clippers adjusts the bare blade between roughly 0.5 mm and 1.5 mm: useful for blending below a #1.
• Brands vary slightly but these lengths are near-universal. See our guard numbers guide for which to use per cut.

Which Clipper Guard Size in mm Suits Each Haircut?

How Many mm Does Hair Grow Each Week After a Clipper Cut?

Hair grows about half an inch a month, which is close to 13 mm, or about 3 mm a week. Since each whole guard number is also about 3 mm, a clipper cut grows roughly one guard size per week. Our hair growth statistics report covers the research behind that figure.

This is why the sides of a fade look soft after one to two weeks. Our guide to how often you should get a haircut gives intervals by style.

What Clipper Guard Size Mistakes Should You Avoid?

• Buying a single guard set and assuming every brand's numbering matches. A #2 on one clipper is not always the same length as a #2 on another, so check the printed millimeter figure rather than trusting the number alone.
• Using the same guard size on wet and dry hair. Clipping wet hair cuts it shorter than the guard suggests once it dries and shrinks back, which is why most guides for at-home cuts assume dry hair.
• Pressing the clipper hard against the scalp to "make sure it cuts." This flexes the guard's teeth and can take hair shorter than the size printed on it, especially on curved areas like the back of the head.
• Going straight to a skin-level guard for a fade without a longer guard first. Skipping steps leaves visible lines instead of a gradual blend between lengths.

Does the Same Guard Size Look Different on Curly Hair?

The same guard number looks different depending on how your hair grows. Straight hair lies close to the scalp, so a given millimeter length shows almost exactly as cut. Curly or coily hair shrinks upward as it dries, so a guard that reads short on straight hair can look noticeably longer on tightly curled hair once it springs back. If you have curly hair and want a true buzz-short look, consider going one guard size shorter than you would choose for straight hair to account for that shrinkage.

How Do You Explain Guard Sizes in mm to a Barber?

Barbers commonly work by guard number rather than millimeters, so it helps to translate what you want at home into that language before your appointment. If you have been maintaining the sides yourself with a #2 guard, say that number along with the brand if you know it, and mention whether that was on wet or dry hair.

For a fade, describe where you want the shortest guard to start (above the ear, at the temple, or lower at the nape) rather than only naming the number, since the starting point matters as much as the length for how the finished fade reads.

What Should You Say to a Barber Abroad?

Outside the US, many barbers think in millimeters, not guard numbers. Give the number in mm for the clipper parts and a finger-width or centimeter length for the scissor parts. A fade is a cut where the sides get gradually shorter toward the bottom, so name both ends of it.

What to say in the chair

“Three millimeters on the sides, faded down to bare skin above the ears, and about four centimeters left on top with scissors.”

• Write the mm figures on your phone before the visit, in case the shop works by number.
• Our clipper guard numbers explained guide shows which guard fits which cut, and fade types explained names each fade height.
• For the rest of the conversation, see how to talk to your barber. For US prices by shop type, see our haircut cost guide.
• If you cut at home, you are not alone; our DIY haircut statistics show how common it is.

Frequently Asked Questions