The numbers are eighths of an inch
That is the whole convention, and it is why the numbers run out at eight.
| Guard | Inches | Millimeters |
|---|---|---|
| #1 | 1/8” | 3 mm (0.12 in) |
| #2 | 1/4” | 6 mm (0.24 in) |
| #3 | 3/8” | 10 mm (0.39 in) |
| #4 | 1/2” | 13 mm (0.51 in) |
| #5 | 5/8” | 16 mm (0.63 in) |
| #6 | 3/4” | 19 mm (0.75 in) |
| #7 | 7/8” | 22 mm (0.87 in) |
| #8 | 1” | 25 mm (0.98 in) |
The millimeter column is the published one. On the Wahl set we cover, Wahl states 3, 6, 10, 13, 16, 19, 22 and 25 mm (0.98 in) — and every one of those is the eighth-inch figure rounded to the nearest millimeter, within half a millimeter throughout. The two columns are not two systems. They are one series written twice.
Why the step matters more than the count
Every step in that table is an eighth of an inch. That is the thing to notice before counting guards: eight guards sound like a lot of choice, and they give you one length of choice repeated eight times.
An eighth of an inch is too coarse to blend. A fade needs increments finer than the gap it is trying to hide, which is why blending is done on the machine — a taper lever, or an adjustable head — rather than by swapping combs. Four settings covering 1 to 4 mm (0.04 to 0.16 in) will blend where eight guards covering 3 to 25 mm (0.12 to 0.98 in) cannot.
So count the steps inside the range you actually use, not the guards in the box, and bridge the gap with clipper over comb and a scaled comb like the Hercules Sägemann 7643M.
Below an eighth of an inch
The guard sets here stop at #1, because a comb thinner than about 3 mm (0.12 in) has nowhere to sit on the blade. Below that, length is set on the machine itself. The Remington HC5811 on this site reaches 0.8 to 2 mm (0.03 to 0.08 in) that way — roughly a thirty-second to a sixteenth of an inch, which is stubble rather than a cut length. The Philips HC5630 goes down to 0.5 mm (0.02 in) on its wheel.
Fit is a blade profile, not a brand
Guards clip onto a blade, and makers change blade profiles between ranges, so a guard that physically fits is not the same thing as a guard that was made for the machine.
Only one of the two sets on this site lets you check it properly. Wahl publishes ten clipper references the combs snap onto, by number. Moser publishes a family — “Moser and Wahl Ermila clippers, per the listing” — which tells you where to look but not whether your machine is on the list. Where a maker gives references, match yours against them before ordering; where it gives a family name, the safest check is the clipper’s own manual.
Color and marking
A guard whose printed number has rubbed off is a guard you stop trusting, and that is the failure that actually happens: not a broken comb, a worn label. The Wahl set gives each comb its own color with the size marked, which survives what printing alone does not. See the rest of them on guide combs.
What people ask about this
Is a #4 the same on every clipper?
The intended length is: #4 means half an inch, about 13 mm (0.51 in), on any set that follows the trade convention. What is not reliable is whether a given set follows it, or whether the guard will even fit — so the figure to compare is the published length, not the number. The [Wahl set](/accessories/wahl-nylon-attachment-combs/) publishes both: #1 to #8 at 3, 6, 10, 13, 16, 19, 22 and 25 mm (0.98 in), which is 1/8" through 1" in eighths.
Will guards from one brand fit another clipper?
Usually not. A guard clips onto a blade profile, and even the same maker changes profiles between ranges. Of the two sets on this site only Wahl publishes the machines it fits by reference number — ten of them. Moser states a family, "Moser and Wahl Ermila clippers", which is a weaker check.
Last reviewed October 12, 2026
