Clipper Guard Sizes 3–25 mm: Exact Chart, Style Uses and Lever Tips
A clipper guard number tells you how many eighths of an inch it leaves on the hair: a #1 is roughly 3 mm (1/8 inch), a #2 is roughly 6 mm (1/4 inch), and the scale climbs to about 25 mm at a #8. Half guards and a bare blade fill in the gaps below that, down to a skin-close finish. When a clipper has the millimetres printed on the guard itself, trust that number over the name printed on the box.
TL;DR:
- A guard labeled #10 is uncommon, so verify its millimetre measurement rather than assuming it aligns with standard eighth-inch increments.
- A #4 guard leaves approximately 13 mm of hair, which is notably longer than a #3 at around 10 mm, making it more suitable for styles requiring extra length.
- When using clipper guards, always check for printed millimetre figures on the attachment for the most accurate length, especially when replacing or combining brands.
- The taper lever can adjust cutting length by about 1 to 1.5 mm, which is essential for smooth blending in fades without switching guards.
- Mastery of blade control and taper lever use outweighs owning a full set of guards in achieving precise, clean fades.
Table of Contents
- Standard clipper guard size chart in mm and inches
- Why the numbering rule breaks down between brands
- Picking guards for buzz cuts, crew cuts and fades
- Using the taper lever and blade choice to fine-tune length
- Technique beats a drawer full of guards
- A clipper kit built for guard work that actually holds up
- FAQ
- Sources
Standard clipper guard size chart in mm and inches
Every guard you will ever clip onto a set of clippers sits somewhere on this scale, and once you know the pattern you can work out an unfamiliar guard without reaching for a chart at all. The numbers below follow the widely used conversion, where a bare blade means no guard at all and the scale runs up through the half sizes before hitting the whole numbers.
| — | 1/2 in | 13 mm | Moving into crew cut and textured top territory | | #6 | 3/4 in | — | Noticeably longer, holds a bit of styleable length | | — | — | — | Long clipper cut, close to scissor-cut length | | #8 | 1 in | 25 mm | The longest of the standard numbered guards |
Beyond #8, most barbers reach for separate long guards or adjustable combs rather than a numbered set, since standard kits rarely go further. Past that length, scissor-over-comb work tends to give better control than a clipper guard anyway. As a rule of thumb, divide the whole number by eight to get inches, then multiply by 25.4 to land on millimetres, which is exactly how the chart above was built.
Why the numbering rule breaks down between brands
The eighths-of-an-inch logic explains why people round off and say “about 3 mm per number”, but that shorthand is an approximation stacked on an approximation. A #4 at a true 1/2 inch is 12.7 mm, yet most charts round it to 13 mm, and that half-millimetre drift adds up by the time you reach a #8.
Brand design adds another layer of inconsistency on top of the maths. Oster and other detachable-blade systems often use their own length codes rather than the snap-on guard numbers most barbers learn first, and several consumer clipper brands skip the number system altogether and print the millimetre figure straight onto the guard, which is actually the more reliable reference when it is available. Attachments are not always interchangeable between brands either, even when the numbers printed on them match.
Before you buy a replacement guard or follow a length instruction from another barber, run through this short check:
- Look for a printed mm figure on the guard itself and treat it as the final word over any number.
- Confirm whether a half guard (0.5 or 1.5) is involved, since these are easy to miss in a quick instruction.
- Check the guard’s fit against your specific clipper model before paying, since number parity does not guarantee physical compatibility.
Picking guards for buzz cuts, crew cuts and fades
Once you know what each guard leaves behind, choosing one for a specific style becomes a matter of matching the look to the length rather than guessing. A few combinations come up again and again:
- Buzz cut: a single pass with a #2 all over gives the classic short, even look with minimal maintenance.
- Crew cut: run a #2 or #3 on the sides and a #4 to #6 on top, so the crown keeps enough length to hold a slight shape.
- Fade: start with the longest guard on top (often a #4 to #6), then step down through #3, #2, #1 and the half guards as you move towards the hairline, finishing with a bare blade at the skin.
A clean fade comes down to sequencing and patience more than any single guard. Work from the top down, always starting longer than you think you need, since it is far easier to take more off than to put hair back. Overlap each pass slightly rather than making one single sweep, and keep checking the cut from the side, back and a mirror angle, since fade lines that look even from the front often are not. Half guards and a light touch on the taper lever are what smooth out the hard edges between each numbered step, and if the blend still shows a visible line after several passes, that is usually the moment to switch to scissor-over-comb or hand the clippers to someone with more fade experience.
Pro Tip: Always cut a test section at the nape before committing to a length across the whole head: it is far easier to correct one patch than an entire fade.
Using the taper lever and blade choice to fine-tune length
A taper lever is what lets you work between the fixed steps on a guard chart rather than being stuck with whole numbers. Closed, the lever gives you the shortest cut the blade allows; opening it typically adds a small amount, often somewhere around 1 to 1.5 mm, which is enough to turn a #1 into something close to a #1.5 without swapping guards mid-cut. That small movement is what professional barbers lean on constantly when blending a fade, since it avoids the visible step that jumping straight between numbered guards can leave.
A few points worth keeping in mind as you build this into your routine:
- Blade sharpness and alignment affect the finished length as much as the guard does, so a dull or misaligned blade can leave hair longer than the guard suggests.
- Replacing blades on schedule, such as the replacement blades built for fade-focused clippers, keeps your cutting length consistent cut after cut.
- For a structured walkthrough of lever technique and blend sequencing, the fade tutorial in our FXDE Academy covers the same steps in more depth.
Technique beats a drawer full of guards
Owning every guard from 0.5 to 8 will not make your fades cleaner. What makes a fade clean is blade control and a confident hand on the taper lever, because that is what lets you move between lengths without a visible step. If we had to prioritise a core set, it would be a bare blade, #0.5, #1, #1.5, #2, #3, #4 and one long guard, paired with time spent actually practising the blend rather than buying more plastic.
— LUNGU
A clipper kit built for guard work that actually holds up
Guard numbers only matter if the clipper underneath them cuts a consistent length pass after pass, which is what we have built the FXDE Barber Edition Clipper around.
Every FXDE clipper carries a one-year warranty, and every tenth clipper sold funds tools for apprentice barbers through the FXDE Giveback, so your purchase supports the next generation of the trade as well as your own kit. If you want to pair the hardware with technique, our FXDE Academy walks through fade sequencing step by step. Visit the FXDE storefront to see the full clipper and blade range.
FAQ
What size is a 10 guard clipper?
Standard numbered guard sets stop at #8, so a “10” is not part of the common chart and most barbers would treat it as a long guard or adjustable comb rather than a true numbered size. If a product lists a #10, check its printed millimetre figure rather than assuming it follows the usual eighths-of-an-inch scale.
Is a 3 or 4 longer haircut?
A #4 is longer than a #3. A #3 leaves hair at roughly 10 mm, while a #4 leaves closer to 13 mm, a difference you can see clearly once the hair is cut.
What size is a 3mm guard?
A 3 mm length corresponds to a #1 guard, which leaves a tight buzz with the scalp still visible through the hair. If your clipper prints millimetres directly on the guard rather than a number, 3 mm is the figure to look for.
What size clipper for a fade?
A fade typically starts with a longer guard on top, often a #4 to #6, and steps down through #3, #2, #1 and the half guards towards the hairline before finishing with a bare blade. The exact starting point depends on how much length you want to keep on top, but the step-down sequence stays the same.