Barber shop hair clippers are equipped with clipper guards that alter the length of the cut. The size of the blade guard used tells the barber a lot about the haircut and gives him a clear picture of the desired result. A client who asks for a number two fade wants a cut that is very close to the head on the sides and back. A client that asks for a number six taper is asking for something much longer. The number used in the description of the cut corresponds to the number of the blade guard used for the cut. If you do not understand clipper blade sizes, you could run the risk of getting a cut that is too short or too long.
Lay the clipper blades out in front of you from smallest to largest. There should be eight clipper blade attachments total. Locate the numbers on the back of each clipper blade next to the clip that holds the blades onto the clippers.
Notice that the number one blade is the shortest, and the number eight blade is the longest. Pick up the number one clipper blade, and locate the small print under the number. Notice that the number one blade cuts the hair to 1/8 inch or 3 mm.
Repeat for the remaining seven clipper guards, taking note of the sizes. Notice that the number two guard achieves a 1/4 inch or 6 mm cut. Number three cuts the hair at a length of 3/8 inch or 10 mm. Number four is a 1/2 inch or 13 mm. The five guard cuts at 5/8 inch or 16 mm. Number six is 3/4 inch or 19 mm. in length. The number seven clipper guard leaves the hair 7/8 inch or 22 mm. long. Number eight is 1 inch or 25 mm.
A zero or no-guard clipper cut takes the hair down to the scalp much like an electric shaver would.
Clippers are equipped with an extension lever that extends the cutting blades one-half size. This makes it possible to turn a number two clipper blade into a two and a half.
Many clipper blades are color coded in order to make it easier for stylists to locate the proper clipper guard without having to look at the numbers each time a blade is selected. However, not all clipper manufacturers use the same colors for each size. So, do not be concerned if the color of the blade is different from what you are used to.