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PawScales

Dog Harness Size Chart

Measure your dog's chest girth at the widest point behind the front legs, then compare it with each brand's chart, because sizes differ. A 22-inch girth is a Ruffwear XS, a Rabbitgoo S, and a Kurgo S. Enter the girth to see your size in each brand.

By Sikander Malik · Updated October 10, 2026 · Sources

in

Widest point of the chest, just behind the front legs.

Your size by brand

Ruffwear · Front Range
XSbetween sizes
Rabbitgoo · No-Pull (classic)
Sbetween sizes
Kurgo · Tru-Fit Smart
Sbetween sizes

"No fit" means this girth is outside that brand's range. Always check the brand's own chart.

Estimates only, not veterinary advice. Ask your vet about your pet’s health.

How to use it

  1. Measure the chest girth: wrap a soft tape around the widest part of the ribcage, just behind the front legs.
  2. Keep it snug but not tight.
  3. Enter the girth in inches or centimeters.
  4. Read the matching size for each brand, and watch for a "between sizes" flag.
A small terrier wearing a black harness, sitting outdoors

Photo: Jean Marc Bonnel / Pexels

The formula, with two examples

Harness sizing is by chest girth, not weight, because two dogs of the same weight can have very different chests. We compare your girth against each brand's published size ranges and flag when you are within an inch of a size boundary, where the next size up often fits better.

Example 1. A 22-inch girth: Ruffwear XS, Rabbitgoo S, Kurgo S.

Example 2. A 30-inch girth: Ruffwear M, Rabbitgoo L, Kurgo L.

What this calculator doesn’t cover

  • Custom or made-to-measure harnesses.
  • Medical, mobility or support harnesses, which are fitted by a professional.
  • Cats.
Ruffwear Front Range
SizeChest girth
XXS13–17 in
XS17–22 in
S22–27 in
M27–32 in
L/XL32–42 in
Source: Ruffwear official size guide.
Rabbitgoo No-Pull (classic)
SizeChest girth
XS11.8–18.5 in
S13.8–23.5 in
M15–27.8 in
L17–33.4 in
XL21–38 in
Source: Rabbitgoo official size guide.
Kurgo Tru-Fit Smart
SizeChest girth
XS12–18 in
S16–22 in
M18–28 in
L24–34 in
XL28–44 in
Source: Kurgo official size guide.

Tips

  • If you are between sizes, size up and tighten the straps. A too-small harness rubs behind the legs.
  • Check the fit: two fingers should slide under any strap, and the harness should not shift when your dog moves.
  • Re-measure growing puppies often, and after a big weight change.
  • Some brands also use neck size. If a brand lists both, make sure both fit.

Questions owners ask

How do I measure a dog for a harness?
Measure the chest girth: wrap a soft tape around the widest part of the ribcage, just behind the front legs, and keep it snug. Some harnesses also use a neck measurement. Compare your numbers with the specific brand’s chart, since sizes differ a lot between makers.
What if my dog is between sizes?
Size up, then tighten the adjustment straps. A slightly larger harness with snug straps is more comfortable than a small one that digs in behind the legs. This tool flags when your girth is within an inch of a size boundary.
How tight should a harness be?
Snug but not restrictive. You should be able to slide two fingers flat under any strap, and the harness should not slip or rotate when your dog moves or pulls. Check especially behind the front legs, where a tight harness rubs.
Front-clip vs back-clip?
A back-clip is comfortable and easy for relaxed walkers. A front-clip gives more steering for dogs that pull, by turning them toward you. Many no-pull harnesses offer both rings. Fit matters more than clip position, so size correctly first.
What size harness for a puppy?
Measure the current chest girth and pick the brand size that fits now, not the adult size. Puppies grow fast, so expect to resize. An adjustable harness buys some time, but recheck the fit every couple of weeks.
Harness size by weight: does it work?
Weight is only a rough guide. Two 40-pound dogs can have very different chests, so a weight-based size often misses. Always measure chest girth and use the brand’s girth ranges, which is what this tool does.

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Sources

Estimates only, not veterinary advice. Ask your vet about your pet’s health.