Dog Grooming Blade Length Chart & Guide [Groomer Explains]

When it comes to dog clipper blades, understanding their specifications is key to achieving the desired grooming results.

Each blade is assigned a number indicating its length, and some may also feature a letter denoting their specific blade type.

Additionally, you have to factor in brand compatibility and the actual material used in the blades construction.

Groomers will use all this information to decide how to best groom their dog. But it can be a bit confusing to new groomers.

To simplify the process, let’s break down the different types of blades and discuss which ones I recommend starting with.

Dog blades vs human blades

Many pet owners initially try grooming their pets with regular human clippers, and it often doesn’t end well.

Why is it not advisable to use human blades

Human hair is softer, and our skin is more sensitive, so blades are designed with human comfort in mind. However, they struggle to tackle the thickness of dog hair effectively.

Dogs have multiple hair types and layers with varying thickness, so you need something powerful and sharp.

While dog clipper blades may be a bit pricier, the ease they bring to the hair-cutting process for your furry friend is well worth it.

Close up of blade teeth. Dog clipper blades have different teeth and are sharper than human blades.

Blade Length Quick Cheat Sheet

The lower the number the shorter the cut.
Blades start at #40 (the shortest) all the way up to #1 (the longest)

  • #40 – 0.3mm
  • #30 – 0.5mm
  • #10 – 2mm
  • #9 – 2mm
  • #7 – 3.2mm
  • #5 – 6mm
  • #4 – 9.5mm
  • #3 – 13mm
  • 1/2″ Clipper Comb – 13mm

Blade length explained in Groomer terms:

  • #40 – Skin bald. Typically used for surgical procedures. Not recommended.
  • #10 – Very short. Best for matted pelts, or for sensitive areas.
  • #7 – Not recommended. I’ll explain more below.
  • #5 – Good all round short blade.
  • #4 – The blade I use most for the short-but-not-shaved look.
  • #3 – You’ll need to do some scissoring afterwards.
  • 1/2″+ – You’ll be doing a lot of scissoring afterwards.

Which Blades Should You Get?

Which blades you use depend on a few factors:

  • Your dog breed
  • Their coat type
  • The current condition of their coat
  • The hair cut your want to achieve

Also keep in mind – you’ll often use a few different blade lengths while grooming, followed by some final scissoring afterwards.

As you may have guessed, it’s impossible for me to answer definitively. But I can give you some general tips.

The main thing to consider is – how much brushing and upkeep do you want to do afterwards? If you don’t want to brush a lot – go shorter.

This is also true if your dog does not enjoy being brushed.

Most professionals prefer using a #4 or #3 blade as it leaves some length which can be scissored to perfection afterwards.

However, if you want something shorter that will require less brushing and upkeep, go for a #5.

Finally, we clip sensitive areas like the bum or sanitary area with a #10.

Paw pads we generally use a #40 or #30, but student groomers have been known to start with a #10 or #15 blade to get used to manuvering between the toes. This is perfectly fine as you start, but a #30 or #40 will leave a longer lasting finish.

A cordless 5-in-1 clipper
A 5-in-1 cordless clipper blade. Notice how it has settings for 5 different lengths in millimeters.

Blade Length Guides

The #10 for matted coats and sensitive areas

The #10 is a very short blade that is often used for digging out matting and tangles. But the teeth are very tight which avoids accidentally cutting your dog. Which can also be used for a very short haircut.

This is also the go-to blade for trimming paw pads, and clipping sensitive areas of the bum and groin.

Why we avoid the #7

The #7 has wider teeth. Wider teeth leave more margin for error. They allow more hair, but also more skin to potentially go through. And because it’s such a short blade, there is very little clearance between the skin and the blade teeth.

The Popular #5

Excellent for short and quick shaves with leaving a little hair, but not skinned bald like a #10. It’s a short, lasting grooming with a safe blade.

The #4 is the “short but not shaved” look

Like the title says – many clients ask for a “short, but not shaved” look, especially for summer trims. In this case I always reach for the #4. It’s a medium-short length that requires a little bit of scissoring afterwards.

The #3 = more scissoring

This blade will require you to do a little bit of finish work with your scissors afterwards. And there will be enough coat left behind that regular brushing is required. This blade is a little more ideal for clients that want a teddy bear trim.

1/2″ or longer = lots of scissoring

Now we’re getting into clipper combs. These are attachments that snap over your blade that allow you to get longer lengths.

For best results, use a clipper comb over a #30 blade if using an A5 clipper, or a 40 blade if using a cordless wahl 5-in-1 type clipper.

Clipping out the pad pads

With The Grain Vs Against The Grain

In all our examples of length we assume the groomer is clipping with the growth of hair – not against.

By clipping against the growth, you are essentially doubling the amount of hair clipped, so it will be much shorter.

For example if you clip a dog in a 4 against the grain it will be approximately the same length as clipping with a 7 blade with the grain.

There are situations where a professional may choose to go against the growth. But as a new groomer I highly recommend you do NOT do this. It is too easy to catch a flap of skin.

Get used of your blade lengths only moving with the growth to avoid clipper burn and choppy haircuts.

Clipping a poodle
Here’s me clipping the body of a poodle. I’m clipping with the growth, not against.

Blade Edge Types

You may have noticed a letter or strange terms following the number on your blade. Here’s a quick rundown:

F or FC (aka Finish Blades)

Some blades will have an F or FC before or after the length number. F stands for ‘Finish’, FC stands for ‘Finish Cut’.

Finish blades have plenty of extra teeth that help avoid accidentally cutting your dog and produce a nice finish. More teeth means it combs more individual hairs up into the teeth to be cut.

W (Wide Blades)

Wide blades are fairly new to the market. These blades are nearly double the width allowing for quick and easy clipping of the body. These are a fantastic time-saver for experienced groomers.

Skiptooth Blades

Not recommended for beginners. And (in my opinion) I think they should be completely avoided.

These blades have very wide open teeth for cutting large amounts of hair without getting caught on tangles. Sounds good in theory – but they are potentially dangerous as they can easily cut skin.

Groomers used to use them often for bulking clipping off dirty dogs that were matted or getting a short shave.

Cat Blades / Anti-static

Cat blades have an anti-static coating on them and tighter teeth. They rarely make a difference and are much more expensive. Some cat groomers swear by them, but they are not necessary in the everyday salon.

Some of my well-worn blades. Notice the bottom one is a 4FW (#4, Finish, Wide).

Steel Vs. Ceramic

Finally, you may have noticed some blades of different build types.

Ceramic are said to stay sharp for a long period of time, and will produce less heat. However, they’re more expensive and difficult to sharpen.

Steel may dull faster and get hotter, but they’re cheaper and a professional will be able to resharpen the blade for a reasonable price. Making steel a cost effective option.

There are pros and cons to each, so blade material is personal preference. In my experience, I like the steel blades as I can have them sharpened, and if they get too hot I swap it out for a cool one.

Keeping Your Blades From Getting Too Hot

Professional groomers will often have multiple sets of the same blade length. When one gets too hot, we swap it out for a cool one.

The hot blade will rest on a ceramic tile or plate to cool off. The ceramic naturally pulls heat away from the blades.

We can reduce heat in other ways.

  • Make sure blades are sharp. Dull blades produce more friction and heat. That means replacing them with brand new ones.
  • Oily and dirty hair will create extra friction. You can prevent this by bathing and brushing before clipping.
  • Apply clipper oil before each use.
Katlin Primrose

Katlin Primrose

​​Katlin is certified master groomer with over 10 years of experience, a registered veterinarian tech assistant (working in emergency, exotics, and general practice), and has won multiple awards in the show ring with her dogs at AKC and CKC.

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