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What size does your dog need?
Three measurements taken at home answer the whole question: nose-to-tail length for the crate, ribcage girth for the harness and snout size for the muzzle. This reference gives the standard size charts, the 2-3 cm clearance checks and the two-finger fit test for each piece of gear.
Every size on this page comes from three numbers you can take at home with a soft tape measure.
For the crate, measure the dog standing from the tip of the nose to the base of the tail. The crate should be 10-15 cm (4-6 in) longer than that figure and roughly as wide as the dog's shoulder height, so there is room to stand and turn without wasted space.
For the harness, wrap the tape around the ribcage 5 cm (2 in) behind its widest part. That single girth number maps directly onto the standard letter sizes, which run from XS at 30-40 cm up to XL at 80-100 cm.
For the muzzle, note the snout's length and circumference. A basket muzzle is not sized to match the snout but to clear it: 2-3 cm of space all around, and enough depth for the jaw to open 5-6 cm.
Add 10-15 cm (4-6 in) to the nose-to-tail measurement and take the next standard size up.
Crates come in five standard steps: 60, 76, 91, 107 and 122 cm — that is 24, 30, 36, 42 and 48 in. A dog measuring 80 cm nose-to-tail needs 90-95 cm of crate, which lands on the 91 cm (36 in) size.
Both directions of error have names. Too small, and the dog cannot stand and turn. Too far beyond the 10-15 cm margin, and the crate stops working as a den — a young dog gains enough room to toilet at one end and sleep at the other, which is the most common reason crate training stalls.
The full size ladder with worked examples is on the Dog Crate Size Chart page.
Harness sizes run from XS (30-40 cm girth) to XL (80-100 cm); collar width follows body weight.
The girth measurement — taken 5 cm (2 in) behind the widest part of the ribcage — is the only number a harness chart asks for. The standard scale starts at XS for a 30-40 cm girth and tops out at XL for 80-100 cm, with lettered steps between.
Collars are chosen by weight class. Dogs over 10 kg wear flat collars 2.5-4 cm (1-1.5 in) wide, spreading the load across the neck. Toy breeds under 5 kg need a narrow 1-1.5 cm (3/8-5/8 in) band.
The conversion from tape reading to letter size, and the closing fit test, are laid out on the Harness and Collar Sizing page.
A muzzle that fits is measured in clearance, not tightness: 2-3 cm around the snout and 5-6 cm of jaw travel.
Two fingers under every strap, and a gentle backward pull the dog cannot slip — that is the whole fit test.
| Gear | What you measure | Standard sizes | Fit check |
|---|---|---|---|
| Crate | Nose-to-tail length | 60, 76, 91, 107, 122 cm (24-48 in) | 10-15 cm (4-6 in) longer than the dog; width near shoulder height |
| Harness | Girth 5 cm (2 in) behind the widest part of the ribcage | XS 30-40 cm up to XL 80-100 cm | Two fingers (2-3 cm) under every strap |
| Flat collar, dogs over 10 kg | Neck circumference and body weight | Width 2.5-4 cm (1-1.5 in) | Two fingers under the collar; dog cannot back out |
| Flat collar, toy breeds under 5 kg | Neck circumference and body weight | Width 1-1.5 cm (3/8-5/8 in) | Two fingers under the collar; dog cannot back out |
| Basket muzzle | Snout length and circumference | Sized to clear the snout, not match it | 2-3 cm clearance around the snout; jaw opens 5-6 cm |
| Walking leash | — | 1.8 m (6 ft) | Clip to a collar or harness that passes the two-finger test |
| Training long line | — | 5-10 m (15-30 ft) | Use for recall training, not street walking |
| Retractable tape lead | Dog's body weight | Rated to about 50 kg (110 lb) | Tape outlasts cord, which kinks and wears twice as fast |
A basket muzzle fits when two fingers of space surround the snout and the jaw can still open 5-6 cm.
The clearance check is 2-3 cm — about two fingers — of free space around the snout. A basket that touches the snout rubs; one that is sized to clear it can be worn without chafing.
The jaw check matters more than the length. The dog must be able to open its mouth 5-6 cm inside the basket, because panting is how a dog cools itself. A muzzle that blocks panting is a misfit whatever the size label says.
Most dogs need a short conditioning routine — about five minutes a day — before wearing a muzzle calmly. The step-by-step version is on the How to Fit a Basket Muzzle page.
Work from collar to muzzle; the first full fitting takes about 20 minutes, plus a week of short muzzle sessions.
The order is deliberate. Collar and harness come first because they are the daily-wear items; the crate follows because the dog has to walk into it willingly; the muzzle comes last because it needs several days of conditioning rather than a single fitting.
After the first fitting, re-run the two-finger test before every walk. Straps settle with wear, and a fit that was right last month can loosen or tighten without anyone noticing.
The list below restates the measurement standards this reference is built on, in the units in which they are commonly published.