How to Measure Your Dog for a Harness — Australian Size Guide
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The most common reason a harness fails — slips off, chafes, or loses its no-pull function — is a bad fit. Not a bad product. A harness that’s too loose gives a determined dog room to back out of it. One that’s too tight restricts movement and causes rubs, sometimes in places you won’t notice until after the walk. Getting the size right is the whole job, and it takes less than two minutes.
This guide covers the exact measurements you need, an Australian size chart for the most common breeds, and how to check the fit once the harness is on.
What You’ll Need Before You Start
A soft fabric measuring tape — the kind used for sewing works perfectly. No tape measure? A piece of string and a ruler will do the same thing.
Your dog standing naturally on all four legs. Not sitting, not lying down. Body posture changes the measurements more than you’d expect.
A second person if your dog is wriggly. One of you holds the dog steady; the other takes the measurements. It’s much easier than wrestling a tape measure solo.
The Two Measurements That Matter Most
Chest girth is the critical one. Wrap the tape around the widest part of your dog’s chest — this is just behind the front legs, roughly where the ribcage is broadest. Keep the tape snug but not compressed. This single measurement determines which size bracket your dog falls into for most harness designs.
Neck circumference is taken just below where a collar would normally sit — the base of the neck, not the top. This matters for harnesses with a neck loop, and it’s useful to cross-reference with the chest measurement when a dog’s proportions are unusual.
Back length — measured from the base of the neck to the base of the tail — is less commonly used but worth taking for long-bodied breeds. A dachshund and a beagle can have identical chest girths but need quite different harness profiles. If you have a corgi, dachshund, or basset hound, note this measurement before buying.
Write the numbers down. Don’t rely on memory, especially if you’re ordering online.
Australian Size Chart — Small, Medium, Large
Sizing varies between brands, and Australian listings don’t always match the US or UK charts the same product might be sold under elsewhere. Always verify against the specific product’s size guide — but as a starting point, here are approximate chest girth ranges:
| Size | Chest Girth (approx.) | Typical breeds |
|---|---|---|
| Small | 36–54 cm | Toy breeds, small terriers, Cavaliers — generally under 10 kg |
| Medium | 46–65 cm | Spaniels, border collies, whippets, medium-sized mixed breeds |
| Large | 57–80 cm | Labradors, German shepherds, golden retrievers, large mixed breeds |
If your dog’s measurement falls between two sizes, go up. A harness that’s slightly too large can be adjusted in. One that’s too tight cannot be made to fit, and forcing it will cause discomfort or rubbing.
Australian sizing can differ from US and UK charts even when buying the same product. Always use the centimetre measurements, not the size label, to make your decision.
The Two-Finger Rule — Checking Fit Once It’s On
Slide two fingers under each strap. That’s the benchmark:
- Can’t fit one finger — too tight. Loosen the strap.
- Two fingers slide in comfortably — correct tension.
- Whole hand goes in — too loose. It needs to come in.
Do this check on each strap separately: the chest strap, the belly strap, and the neck loop. Then take your dog for a short walk and recheck. Harnesses settle with movement — straps that felt snug standing still will sometimes loosen once the dog is moving.
The Reflective No-Pull Dog Harness & Leash Set comes in Small, Medium, and Large with fully adjustable straps — run through the two-finger check on each strap once it’s on.
Common Fit Mistakes
Measuring over a thick collar. Always measure on bare fur. A thick padded collar can add 2–3 cm and push you into the wrong size.
Measuring after a big meal. A dog’s chest girth can increase by 1–2 cm after eating. Measure before a meal, not after.
Not rechecking after a seasonal weight change. Dogs often gain condition over winter. A harness that fitted well in March can be uncomfortably snug by July. If your dog seems reluctant to have the harness put on, or if you notice redness beneath the straps, re-run the two-finger check.
Finding the Right Harness
Once you have your dog’s chest girth measurement, sizing becomes simple. If you’re after something that works well on evening walks — when visibility is low and a standard lead attachment isn’t enough to keep a puller under control — the Reflective No-Pull Dog Harness & Leash Set is worth a look. It comes in Red or Green, in Small, Medium, and Large, with reflective stitching and a front clip for dogs that pull. Measure first, pick your size from the product chart, and adjust the straps once it’s on.