Clipper Guard Numbers Explained: What They Mean for Your Haircut

Clipper guards are the plastic attachments that fit over a clipper blade, determining the length of hair left behind when the clipper passes through. Each guard is numbered, and the number corresponds to a specific hair length in eighths of an inch (in the US standard system). Knowing what each number means lets you communicate precisely with your barber about how short you want specific sections cut.

The Standard Guard Numbers and Lengths

In the US standard system, each guard number represents one eighth of an inch of hair length left after cutting.

Guard 0 (bare/open): no guard, just the bare blade. Cuts to approximately 1.5mm (about 1/16 inch). The shortest clipper cut without shaving with a razor. Used for skin fades and very close sections.

Guard 1: approximately 3mm (1/8 inch). Very short, scalp clearly visible through the hair. Used for skin-adjacent sections in fades and for the shortest buzz cuts.

Guard 2: approximately 6mm (1/4 inch). The most common "short buzz" length. Short but not shaved — hair is present and visible but the scalp can be seen through it. Very common for the sides of fades and for butch-style buzz cuts.

Guard 3: approximately 10mm (3/8 inch). Medium-short. Hair has visible texture and direction. Used as a standalone top length for medium-short cuts or as the longest section in many fade tops.

Guard 4: approximately 13mm (1/2 inch). Medium length. Enough hair to show texture and movement. Common top-section length for crew cuts and many standard men's cuts.

Guard 5 to 8: lengths ranging from 16mm to 25mm (5/8 to 1 inch). These longer guards are used for the top sections on longer cuts and for blending between sections. At these lengths, scissor cutting becomes increasingly relevant alongside clippers.

CADMEN Training

Clipper technique and guard selection are core skills in CADMEN's hands-on barbering program. academy.cadmen.ca/in-person-training.

Frequently Asked Questions

What do the numbers on hair clippers mean?

Clipper numbers refer to the length of hair left behind after cutting, measured in increments of 1/8 inch (3mm) in the standard US system. The rule: guard number x 1/8 inch = hair length remaining. Guard 1 = 1/8 inch = about 3mm. Guard 2 = 2/8 inch = 1/4 inch = about 6mm. Guard 3 = 3/8 inch = about 10mm. Guard 4 = 4/8 inch = 1/2 inch = about 13mm. Guard 5 = 5/8 inch = about 16mm. Guard 6 = 6/8 inch = 3/4 inch = about 19mm. Guard 7 = 7/8 inch = about 22mm. Guard 8 = 8/8 inch = 1 inch = about 25mm. The guards also have half sizes in many sets (1.5, 2.5, 3.5, etc.) for more precision between the main numbers. Important caveat on the metric numbers: different clipper brands can vary slightly in exact mm length per guard. The numbers above are the industry standard approximations, but a Guard 2 from Wahl may leave slightly more or less hair than a Guard 2 from Andis or Oster, depending on the blade gap and guard design. The half guards mentioned above help bridge these gaps. For fades, barbers often blend between guard sizes (using a 1.5 between a 1 and a 2, for example) to create smooth graduation without visible lines. At or below guard 0, the bare clipper blade runs at approximately 1mm to 1.5mm. Below this, a razor is required to reach skin level for a true skin fade. The barber's technique matters beyond the guard: the angle at which the clipper is held, whether it is taken against or with the growth pattern, and where the barber starts and stops the pass all affect the result as much as the guard number does.

What guard should I ask for my haircut?

The guard to ask for depends on which section you are specifying and how short you want that section. The most common scenarios: for the sides and back of a fade or short haircut — starting point. Guard 1 (3mm): very close sides, scalp visible. Guard 2 (6mm): short sides, some hair coverage. Guard 3 (10mm): medium-short sides with visible texture. These three numbers cover the range from "very close" to "moderate" for the sides of most men's haircuts. For the top section of a short haircut. Guard 3 (10mm): short top with texture. Guard 4 (13mm): medium-short top. Guard 5 to 6 (16 to 19mm): medium-length top. For a uniform buzz cut (same length all over). Guard 2: very short, not shaved. Guard 3: short but with visible hair. Guard 4: medium short with texture. For fades specifically. You do not always need to specify the individual fade guard numbers — most barbers handle the gradient between skin and the longer top section based on the starting and ending lengths you specify. Telling the barber the top length (guard 4 or 5), the side finish (skin, guard 1, or guard 2), and the fade type (low, mid, or high) gives enough information for an experienced barber to create the gradient. If you are genuinely uncertain what to ask for: showing a reference photo and asking the barber what guards they would use for that look is a straightforward approach. The barber translates the visual into the technical, and you get the cut you want without needing to memorize guard-to-mm conversions.

Is there a standard set of clipper guard sizes across all brands?

The guard numbering system (1 through 8, with the 1/8-inch-per-number convention) is widely used as an industry standard, but the exact physical lengths can vary slightly between brands because different brands have slightly different blade gaps and guard designs. The main clipper brands used in professional barbershops are Wahl, Andis, Oster, and Babyliss. These brands all use the same numbering convention and produce guards that are close to the standard lengths, but there are small variations. A Wahl Guard 2 and an Andis Guard 2 will leave approximately the same length (around 6mm), but "approximately" is the key word — there can be a 0.5mm to 1mm difference in actual cut length between brands on the same guard number. This is relevant for precision fade work where a barber uses guards from multiple brands or blends with half-guards to create smooth gradients. For client communication, the standard number convention works reliably — when you say "guard 2 on the sides," any barber with professional clippers understands what you mean within the practical margin of the standard. Where it matters more to the barber than the client: in the transition zones of a fade, the barber uses half guards (1.5, 2.5, etc.) to blend between whole-number guards smoothly. Some brands sell comprehensive guard sets with half sizes; others only include whole guards in their standard sets. Home clippers: consumer clipper sets often use the same numbering convention, but the guard lengths can deviate more from the professional standard than professional-grade clippers do. If you are assessing a guard on your home clippers versus what a barber would use, the numbers are directionally the same but should not be assumed to be identical in cut length.