Dog Clipper Guard Sizes Explained: Length Chart and Tips
Guard and blade numbers are confusing, partly because different brands use different systems. A little understanding avoids a haircut that is shorter than you intended.
Blades versus guards
Blades have fine teeth that cut the hair. They are numbered, and a higher number means a shorter cut. For example, a number ten blade leaves hair about 1.5 millimetres long, while a number four leaves about 9.5 millimetres, depending on the brand.
Guards, also called combs or attachment combs, clip over a blade and leave extra length. They are marked with a number or length in millimetres or inches.
Typical blade lengths
| Blade | Approximate length |
|---|---|
| 10 | 1.5 mm |
| 7F | 3 mm |
| 5F | 6 mm |
| 4F | 9.5 mm |
| 3F | 13 mm |
Lengths vary by brand, so check your manufacturer's chart. Surgical blades, such as a number 40, cut extremely close, and are used by groomers only for specific purposes.
Typical guard lengths
Guard sets often range from about 3 millimetres up to 25 millimetres or more. Always check the length stamped on the guard, since numbering differs.
Choosing a length
- Short summer clip: 6 to 13 millimetres, depending on coat.
- Puppy cut or teddy bear cut: 13 to 25 millimetres.
- Neat tidy-up: 20 to 32 millimetres.
- Sanitary areas: short blade, with care. See how to do a sanitary trim.
Coat considerations
- Curly coats: a longer guard is easier to maintain and looks softer. See curly-coat grooming.
- Silky coats: medium lengths work well. See silky-coat grooming.
- Double coats: avoid short clips unless a vet advises. See double-coat grooming.
- Wire coats: clipping softens the coat. See wire-coat grooming.
Skin sensitivity
Very short blades can cause clipper burn and sunburn. Use longer guards for sensitive dogs. Protect shaved skin from sun.
Starting out
Pick a longer guard than you think you need and do a test on the back. If the length is not right, go shorter. See how to give a dog a puppy cut at home.
Compatibility
Guards fit specific clipper models and blade sizes. Check that yours are compatible. See best dog clippers for home grooming.
Maintenance
Clean guards to remove hair, check for cracks and replace broken ones.
A practical example
Say you want to give a Poodle mix a teddy bear look. A 19-millimetre guard on the body gives a soft, even coat. Use scissors for the face and legs, which you might leave slightly longer for a fluffy shape. If the result feels too long, go down to 13 millimetres on the next session. Keeping notes on which guard you used and the date helps you repeat or adjust the cut.
Blade sizes and skin safety
Very short blades sit close to the skin, which means more risk of irritation, cuts and sunburn. They are meant for experienced groomers and specific areas such as the sanitary region. For routine pet clipping at home, longer guards are safer and more forgiving. Keep a spare guard in case one breaks, and replace any that are cracked.
Reading a manufacturer's chart
Brands publish charts that show the length of each blade and guard. Print the chart and keep it with your tools. If you change brands, check the numbers again, because equivalent sizes may differ by a millimetre or two.
The takeaway
Know whether you are using a blade or a guard, check the length on the product and start longer. You can always go shorter.
Frequently asked questions
What is the difference between a blade and a guard?
The blade cuts the hair, while the guard fits over it to leave extra length.
What guard gives a puppy cut?
Often a longer guard, around 10 to 20 millimetres, but check the brand chart.
What blade size is used for sanitary areas?
Often a short blade such as a number ten, used with care.
Are guards the same across brands?
No. Check the length marked on each guard.