How to measure your dog for a harness
Measure the chest girth: a soft tape right round the deepest part of the ribcage, just behind the front legs, snug against the coat with room for two fingers underneath. That one number is what every harness brand sizes by — and the same number at every brand, which is why it is worth getting right once.
Four steps
- Stand the dog square. Measure with your dog standing on all four feet, head up and weight even. Posture and movement can change the reading. Let the dog settle, then check the reading again.
- Find the deepest part of the ribcage. Run a hand down behind the front legs to where the chest is fullest — usually two or three finger-widths behind the elbows. Not the neck, not the belly.
- Wrap the tape right round. A soft tailor’s tape, flat against the coat, level all the way round. No tape? Use string or a phone charger cable, mark where it meets, and measure that against a ruler.
- Snug, not tight — then read it. You should be able to slide two fingers flat under the tape. Read the number where the tape meets its start. That is the chest girth, and it is what every brand sizes by.
The mistakes that send harnesses back
Measuring the neck
Collars size by neck; harnesses size by chest. A neck measurement in a harness chart buys a harness a size or two too small.
Measuring over a harness or a thick winter coat pulled tight
Measure against the coat as it is normally kept, not through it, and not over another harness. Re-check after a groom.
Going by weight
Weight does not replace a chest measurement. Published weight guidance only helps choose between sizes whose girth ranges already cover the reading.
Rounding a reading to make a size fit
Use the measurement you took. Near the lower end of a size’s printed girth range, the straps are close to their tightest; near the upper end, they are close to their loosest. Check the maker’s fitting instructions and that the harness can adjust securely on your dog.
Treating a chart gap as an overlap
An overlap means more than one printed size covers the reading. A gap means none does. Re-measure first; if the reading still falls in the gap, check the maker’s guidance or compare another chart.
Dogs that make it harder
A dog that will not stand still — measure with a second person, or take a quick reading at the end of a walk when it is calmer; there is a whole guide to it. A deep-chested breed (Greyhound, Whippet, Dachshund) — the deepest point is further back than it looks, so feel for it rather than guessing. A puppy — the number changes every few weeks; re-measure before every purchase, or save your dog’s record.
Your breed’s page has notes on where its build makes measuring awkward: find your breed.
Now turn the number into a size
Type the girth and see the size at every brand, and where inside each size’s range your dog sits.
Around the chest, just behind the front legs. Measuring guide.
Type the chest girth and the size appears for all 12 harnesses — Julius-K9 · Ruffwear · PetSafe · Kurgo · Blue-9 · Rabbitgoo · Puppia · PetSafe 3 in 1 · Dog Friendly Co · PawSafe · Wonder Walker · Top Paw — with where your dog sits inside each size.
Before you order — the two-finger rule · full measuring guide
- Measure the deepest part of the ribcage, just behind the front legs, with the dog standing.
- Two fingers should slide flat under any strap. A whole hand means it is loose enough to reverse out of.
- Snug against the coat, not pulled tight through it — and re-check after a groom.
Ranges are transcribed from each manufacturer’s own chart. See the full conversion chart or how we check these numbers.
Already own a harness that fits? Convert its size to every other brand instead.