What a number two actually leaves on your head

The ladder, and whose ladder it is

On Wahl guide combs the whole numbers step in eighths of an inch. A number one leaves an eighth of an inch, which the same maker gives as 3mm, a number two leaves a quarter, and the run continues in those steps to a number eight at one inch, which Wahl lists as 25mm. The half sizes fill the gaps between them: a half guard at a sixteenth of an inch, listed as 1.5mm, and a one and a half at three sixteenths.

The same maker also sells combs past the end of that run, a number ten at an inch and a quarter and a number twelve at an inch and a half, which exist for work that is really scissor length being done with clippers.

That is the ladder nearly every chart on the internet reproduces, and it is accurate for the brand it came from. The problem is that it gets presented as an industry standard, and it is not one.

The number is a slot in a set, not a measurement

Andis numbers its snap-on combs per set rather than against one shared ladder. A four comb set runs zero to three and lands on a sixteenth, an eighth, a quarter and three eighths of an inch. A master set is numbered zero, one, two, three, four, six and eight, so the numbers themselves skip. An eleven comb set fills in sizes the usual run leaves out entirely, among them three thirty seconds, three sixteenths, five eighths and seven eighths.

There is even a set whose smallest comb is longer than the longest comb on the standard ladder: an eight piece universal set that starts at five eighths of an inch and climbs to an inch and a quarter in sixteenths, built for detachable blades rather than for the clipper most people picture.

Combs are also not interchangeable inside one brand. Each of those sets names the clippers or the blade sizes it fits, which is the line every chart drops, and it is the reason the number on your cousin clippers at home may not be the number in the chair.

What to say out loud instead

None of this means the numbers are useless. It means a number on its own is half an instruction, and the other half costs you one extra clause.

• Give the fraction or the millimetres as well as the number. A barber who hears a quarter of an inch on the sides has nothing left to guess at, whatever the combs in the drawer are called.
• Name the shape in the same sentence. Short at the sides describes a length. Short at the sides, blended up into the length on top, with a straight edge at the front, describes a haircut.
• If you are cutting at home, read the length printed on the comb rather than counting positions in the case. A kit with half sizes in it puts the fourth comb at a different length from a kit without them.
• Keep one number as your own reference. Once you know what a given comb left on your head and how it looked at week three, that is worth more than any chart, because it already accounts for your hair.

Why the number decides less than you think

Two heads cut with the same comb do not look the same, and the variable is not the length. It is how much scalp shows through at that length, which is a question of density and of how much contrast there is between the hair and the skin underneath it.

Dense hair at a quarter of an inch reads as a solid block of colour. The same quarter of an inch on finer hair reads as a soft haze with the scalp visible through it, and a reader who went in with a photograph of the first will think the barber cut it wrong. Nobody cut it wrong. The photograph was of different hair.

Growth direction does the rest. A cowlick or a whorl at the crown sits flat at one length and stands up at the next one down, so the number that works on the sides is not automatically the number that works on top.

A fade is several numbers and the work between them

The phrase that causes the most confusion is a number two fade, because a fade is not a length at all. It is a gradient, which means several combs used in sequence and a blend worked between them, and the comb you name is only one point on that gradient.

What actually decides how a fade looks is where the shortest point sits and how high the change climbs, not the number at the top of it. Two heads can both be honestly described as a number two fade and look nothing alike, because one is taken to skin at the bottom and climbs past the temple while the other starts at the number two and stays below the ear.

So if a fade is what you want, the useful request names the bottom, the top and where the two meet, and leaves one number as shorthand for the rest. The fade guide on this site sorts the named fades by exactly that, and the style pages show the finished gradient on a face rather than as a diagram.

The common requests, read as outcomes

Translating the usual asks into what you end up with is more useful than any conversion table, because this is the form the request actually arrives in.

• One all over. The shortest length most people are comfortable with, and the point where the outline at the hairline starts carrying the whole haircut, because there is no length left to hide a crooked edge.
• Two on the sides, scissors on top. The standard safe request and the one most likely to come out close to the photograph, because the part that varies by hair type is being cut by eye rather than by comb.
• Zero, or no comb at all. Different things. Zero is a comb on some sets. No comb is the blade on its own, so the length is then set by the blade and the barber hand rather than by anything you can name in advance.
• A buzz, meaning one comb everywhere. Honest and quick, and it lives or dies on the edge at the front and the temples rather than on which comb was used.

Settle the look, then pick the number

The number is the last decision, not the first one. What you are really choosing is a finished shape, and the comb is just the tool that produces it on your particular hair, which is why the same number is the right answer for one person and the wrong one for the person in the next chair.

That is the order Lineup is built for. Render the cut on your own selfie first, see what the shape does to your hairline and your density, and then walk in and name the length with the shape attached to it. It is a cheaper way to find out than a fortnight of growing something back.

See these on your own face

• buzz cut
• low taper fade
• mid taper fade
• burst fade
• edgar cut

Questions