Choosing the Right Guard Length

How Guard Lengths Work: Numbers, mm and the Look

Choosing the right guard length starts with understanding what a guard actually does. A guard comb, sometimes called an attachment comb, clips over the clipper blade and lifts the coat so the blade cuts at a set distance from the skin. The higher the guard number, the more hair it leaves behind. Guards are commonly numbered, and each corresponds roughly to a length in millimetres, so once you know the millimetres you can picture the finish regardless of the brand’s numbering.

As a practical map, the common guards break down like this:

• 3mm (around a No. 1): a short, neat trim that follows the body shape closely without being shaved
• 6mm (around a No. 2): a versatile everyday length, tidy but with a little coat left for protection
• 10mm (around a No. 3): a fuller, softer look that keeps more of the coat’s texture
• 13mm (around a No. 4): a longer, fluffier finish that still evens out the coat
• 16mm (around a No. 5 and up): the longest guards, taking off only the tips for a light tidy

Numbering varies between manufacturers, so always check the millimetre figure printed on the guard rather than relying on the number alone.

3mm vs 6mm vs 10mm vs 13mm vs 16mm in Practice

Seeing how these lengths differ in practice makes the choice far easier. A 3mm guard gives a close, sleek result that shows the dog’s outline and is easy to maintain, but it leaves less coat to protect against sun and scratches. A 6mm guard is the workhorse for most pet trims: short enough to stay tidy between grooms, long enough to look natural and keep some insulation. Move up to 10mm and the coat starts to feel plush and fluffy, holding its texture and hiding minor unevenness.

At 13mm and 16mm you are barely reducing bulk, simply neatening the tips and tidying the silhouette, which suits owners who want length kept but shape improved. Remember that the same guard produces a slightly different look on different coats: a dense coat clips fuller than a fine one at the identical setting. This is exactly why using clippers safely and testing a small patch first both matter. When in doubt, size up, because a fraction too long is easily corrected and a fraction too short is not.

Match Guard Length to Breed and Coat Type

Coat type should drive your guard choice more than fashion. Curly and continually growing coats, as on poodles, doodles and bichons, take a guard well and can be clipped to almost any length; 6mm to 13mm keeps them neat without shaving the character out of the coat. Silky-coated breeds such as cocker spaniels are often clipped shorter on the body with longer feathering left by hand. Terriers with wiry coats have their own considerations, as clipping softens the harsh texture over time, so many owners accept that trade-off for the convenience.

Double-coated breeds like huskies, German shepherds and many collies are the big exception. As a rule you should not clip a healthy double coat, because it disrupts the coat’s natural insulation and the way it regrows, and it removes the protection the coat provides in both heat and cold. For these dogs, brushing and deshedding are the answer rather than clippers, and deshedding a double coat without damage explains the correct approach. Choosing the right guard length also means recognising when no clipper should be used at all.

Avoid clipping a healthy double coat unless a vet or professional groomer advises it, as it can permanently alter regrowth and remove the coat's natural insulation and sun protection.

Go Longer First, Then Reduce

The golden rule of choosing the right guard length is to start longer than you think you need and work down. Fit a longer guard, complete a full pass, then step back and assess before deciding whether to go shorter. Hair grows back slowly, and an over-short clip can leave your dog cold, exposed to sunburn on pale skin, and prone to irritation, none of which you can undo once the coat is off. Going longer first costs you a few extra minutes at most; going too short costs weeks of regrowth.

This approach is especially valuable when you are trimming an unfamiliar dog or a new coat type, because you cannot fully predict how a coat will sit until you have made a pass. Keep a metal comb to hand and comb the coat up between passes to check the true length and reveal any unevenness. If the finish is still too long after the first pass, drop down one guard and repeat. A methodical, cautious sequence gives a more even result and a far calmer dog than trying to nail the shortest length in a single go.

Face vs Body: Choosing Different Lengths

You will rarely use a single guard length across the whole dog. The body carries the longest coat and sets the overall style, while the face, ears, feet and tail usually need shorter or more careful work with scissors or a smaller guard. A common pet trim pairs a medium body length, say 6mm or 10mm, with a neater face done by hand for expression and safety. Never run clippers close to the eyes; blunt-tipped scissors give you the control that guards cannot near such delicate features.

Legs are often left a touch longer than the body for a balanced look, and feathering on the ears, tail and trousers is typically shaped with scissors rather than clipped flat. Sanitary areas around the groin and rear are trimmed short and tidy for hygiene, taking care over the loose skin there. Planning these zones before you start, and choosing a guard for each, gives a cohesive finish. Pairing the right lengths with sound technique from our clipper safety guide is what turns a home clip into a professional-looking one.