What size harness does a Australian Shepherd need?
The breed standard puts a Australian Shepherd at 16–29kg (35–64lb). Weight narrows the choice at every brand but settles it at none. 2 brands size by girth only and are left blank rather than guessed.
What that weight means at each brand
| Brand | Size | What it means |
|---|---|---|
| Julius-K9 | 0 or 1 or 2 | The breed's weight range spans 3 Julius-K9 sizes (0, 1, 2), so weight alone cannot pick between them. The chest measurement decides. |
| Ruffwear | measure | Ruffwear sizes by chest girth only and publishes no weight guidance, so a Australian Shepherd's weight cannot be converted to one of their sizes. Measure the chest and the tool above will answer it exactly. |
| PetSafe | Medium or Medium/Large | The breed's weight range spans 2 PetSafe sizes (Medium, Medium/Large), so weight alone cannot pick between them. The chest measurement decides. |
| Kurgo | Medium or Large | The breed's weight range spans 2 Kurgo sizes (Medium, Large), so weight alone cannot pick between them. The chest measurement decides. |
| Blue-9 | measure | Blue-9 sizes by chest girth only and publishes no weight guidance, so a Australian Shepherd's weight cannot be converted to one of their sizes. Measure the chest and the tool above will answer it exactly. |
Blank entries are deliberate. Ruffwear and Blue-9 publish no weight guidance to convert, and printing a size anyway would be a guess dressed as an answer.
Now measure, and get the exact size
A breed weight range covers both sexes and every build, which is why it spans more than one size almost everywhere. One measurement replaces all of it.
Measure right around the deepest part of the ribcage, just behind the front legs.
6 size ranges overlap here. The marker shows where your dog falls inside each one — nearer the middle means more adjustment room either way.
How to measure a Australian Shepherd
Take a soft tape right around the deepest part of the ribcage, just behind the front legs. Keep it snug against the coat rather than pulled tight — you should be able to slide two fingers under it. That single number, the chest girth, is what every brand on this page sizes by. Weight is only ever a tie-breaker.
Why the answer is a range, not a number
Every page that hands you one size for a Australian Shepherd is hiding the same problem: the breed standard covers a 81% spread in weight between the lightest and heaviest adults, and girth varies more than weight does. Two Australian Shepherds on the same scale reading can be a size apart. The honest answer is the shortlist above plus the tape.
Other large breeds
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- What size harness does a German Shepherd need?
- What size harness does a Poodle (Standard) need?
- What size harness does a German Shorthaired Pointer need?
- What size harness does a Boxer need?
- What size harness does a Doberman Pinscher need?
- What size harness does a Cane Corso need?
Weight range from the breed standard, read 2026-08-25. Sizes come from each manufacturer’s own published chart — nothing on this page is estimated or averaged between brands.