Almost every harness returned to a retailer was ordered from a breed name. It is a completely reasonable thing to do — you know what your dog is, the box has a size on it, and somewhere on the listing there is a chart with breeds printed down the side. The problem is that a breed describes a shape, and a harness is sold against a circumference, and those two things are only loosely related.
So this chart is deliberately built the other way round. Each row gives the chest-girth range that breed usually falls into, and the harness size that range normally corresponds to. Use it to work out which two sizes are plausible, then measure. The tape settles it in about fifteen seconds and it is the only step that actually protects you from a return.
Measure here, not anywhere else
Run a soft tape around the deepest part of the ribcage, directly behind the front legs, and pull it snug without crushing the coat. That single number — the chest girth — is what nearly every harness size chart is built from. Ruffwear’s own sizing instructions and Kurgo’s describe the identical measurement, which is a useful signal: when two brands that otherwise share nothing agree on the method, the method is the standard.
Some harnesses ask for a neck measurement too. Take it at the base of the neck where a collar would sit, not up under the jaw. And if your dog is mid-coat-blow or has just been clipped, remeasure — a double coat can be worth an inch and a half of apparent girth, which is enough to move a dog a whole size.
Girth ranges by breed
Ranges below span typical adult females at the low end to typical adult males at the high end. A dog outside its breed’s range is not unusual; it is just a dog. The size column is the band that range normally lands in across mainstream harnesses — always check the specific brand’s chart, because the labels genuinely do not transfer.
| Breed | Typical chest girth | Usual size band |
|---|
| Chihuahua | 11–16 in | XS |
| Yorkshire Terrier | 12–16 in | XS |
| Pomeranian | 13–18 in | XS–S |
| Dachshund (standard) | 16–22 in | S |
| Shih Tzu | 16–21 in | S |
| Miniature Schnauzer | 17–22 in | S |
| Jack Russell Terrier | 16–21 in | S |
| Pug | 18–24 in | S–M |
| French Bulldog | 19–26 in | M |
| Boston Terrier | 18–24 in | S–M |
| Beagle | 19–25 in | M |
| Cocker Spaniel | 21–27 in | M |
| Cavalier King Charles Spaniel | 17–22 in | S |
| Border Collie | 24–30 in | M–L |
| Australian Shepherd | 25–32 in | L |
| Bulldog (English) | 24–31 in | M–L |
| Staffordshire Bull Terrier | 22–28 in | M |
| American Pit Bull Terrier | 24–32 in | L |
| Whippet | 22–27 in | M |
| Springer Spaniel | 24–30 in | M–L |
| Poodle (standard) | 24–31 in | L |
| Boxer | 26–34 in | L |
| Labrador Retriever | 27–36 in | L |
| Golden Retriever | 26–35 in | L |
| German Shepherd | 28–38 in | L–XL |
| Doberman | 28–36 in | L–XL |
| Husky | 26–34 in | L |
| Rottweiler | 30–40 in | XL |
| Great Dane | 32–44 in | XL |
| Bernese Mountain Dog | 30–42 in | XL |
The four breeds this chart gets wrong
Every size chart has the same blind spots, and they are all cases where the dog’s proportions rather than its size are the problem.
- Deep-chested sighthounds — greyhounds, whippets, salukis. The ribcage girth suggests one size and the waist is dramatically narrower, so a harness sized to the chest slides backwards on the walk. These dogs want a harness with an independently adjustable belly strap, not a bigger size.
- Brachycephalic breeds — French bulldogs, pugs, bulldogs. A neck close to the width of the skull means an overhead harness often will not pass, and a barrel chest means the girth reading is at the top of the band while the dog is short. Size on girth, then check the neck opening separately.
- Long-backed breeds — dachshunds, corgis, basset hounds. Girth may say Small while length says otherwise, and a harness that is correct at the chest can sit badly along the back. Shape matters more than size here.
- Heavy double coats — huskies, chows, Newfoundlands. Measure twice a year. The same dog genuinely measures differently in January and July, and a harness fitted to a winter coat is loose enough to escape from in August.
