Clipper guards are the plastic combs that clip onto your trimmer and decide how much hair gets left behind. The confusing part is that they get called two different things. Some people ask for a “number 3”, others ask “what guard is 10mm”, and both can mean the same cut. This chart clears it up so you get the length right the first time, whether you are cutting at home or telling a barber exactly what you want.
Clipper guard size chart
Here is how the standard guard numbers line up with their length in millimetres. A higher number leaves more hair on.
Number 1 = 3mm
Number 2 = 6mm
Number 3 = 10mm
Number 4 = 13mm
Number 5 = 16mm
Number 6 = 19mm
Number 7 = 22mm
Number 8 = 25mm
So if someone asks what guard is 16mm, the answer is a number 5. What guard is 10mm? A number 3. And 6mm is a number 2. There is also a half guard on many sets, a 1.5, which sits at around 4.5mm for when a 1 is too short and a 2 is too long.
A quick word on brands
The numbers above are the industry standard and hold true for most clippers, but they are not guaranteed across every make. A few brands run their own sizing, so a guard from one set will not always match the millimetre length of another. If precision matters, check the length printed on the guard itself, or buy the combs made for your specific machine. You can see matched guards and clippers together in the clippers and trimmers range. If you want the technical background on how clippers and their attachment combs work, this overview of hair clippers is a good primer.
Which guard should you use?
For a very short back and sides, most people reach for a 1 or 2. A 3 or 4 gives you a fuller, softer finish that hides unevenness better, which makes it the safest choice if you are cutting your own hair for the first time. Always start longer than you think you need. You can go shorter in a second pass, but you cannot put hair back once it is on the floor.
Work with the growth for an even cut, keep the clipper moving, and comb through as you go to catch any longer strands. Once you have the right guard on, the machine does most of the work for you.
