How To Measure Your Dog For A Hiking Backpack Fit | Girth First, Every Time

Get that one number right and the rest of the fit falls into place. Get it wrong and you’ll be mailing a pack back, or watching a loaded dog shift and stumble on a descent. The job takes about two minutes and one soft tape measure.

Below: the exact measuring sequence, the size chart Ruffwear publishes, and the two things — weight limit and between-size calls — that decide whether the pack works on the trail.

How Do You Measure A Dog For A Backpack?

Measure girth with the dog standing square on all four legs, tape snug around the widest part of the chest just behind the front legs. Measure back length only if the dog lands between sizes.

Ruffwear’s guidance is consistent across its pack line: the tape goes around the widest part of the rib cage, not across the shoulders or belly. Keep it snug but not tight — some guides call for room to slide two fingers under the tape. A squished measurement reads smaller than the dog; a slack one reads bigger.

Two mistakes account for most bad measurements:

• Measuring a sitting or crouched dog. The rib cage compresses and the number comes out short. Stand the dog up, treat in hand if needed.
• Measuring over a thick coat with a stiff tape. Use a soft cloth tape; if the dog has a heavy winter coat, measure the same way you’ll hike — most packs sit over fur, not under it.

Write the girth number down before anything else. That’s the number the size chart wants.

Reading The Ruffwear Size Chart

Ruffwear sizes its dog backpacks primarily by girth, and the published chest ranges for the smaller sizes are the ones most owners need.

The Hitch Hiker Dog Backpack Carrier — the pack that doubles as a carry bag for tired dogs — comes in XXS, XS, and S. The Approach Dog Backpack and the Palisades Dog Backpack use the same girth-based approach, and the same chart carries across related Ruffwear packs and jackets, so one measurement can serve more than one product family.

Between Sizes, Weight Limits, And What The Chart Won’t Tell You

When girth lands between two sizes, use back length — base of the neck to base of the tail — as the tiebreaker, and size up. A slightly roomy pack adjusts down; a tight one rubs.

Back length is also the honest check on proportion. Ruffwear notes that how high or low a dog sits in the Hitch Hiker depends on the dog’s body shape, not just girth — a long-backed dog and a deep-chested dog with the same girth ride differently.

The weight rule matters more than the size label. A 40-pound dog tops out at 10 pounds total. Weigh the loaded pack on a kitchen scale before the first hike; most owners overestimate how much a full water bladder adds.

Once the fit is dialed in, matching the pack to your terrain — saddlebags for a long haul, a lighter load for day trips — is the next decision. Our tested roundup of the best dog backpacks for hiking walks through which models suit which dogs and trail types.

If you’re buying from Ruffwear directly, the Hitch Hiker Dog Backpack Carrier product page carries the current size chart and fitting notes.

Quick Fit Check Before You Load It

Straps should sit flat with the pack centered over the rib cage, not sliding toward the neck or hips. Slide two fingers under each strap; if you can’t, loosen it, and if you can fit a whole hand, tighten it. Load the pack with weight low and even on both sides, then walk the dog around the block before committing to a trail.