How to Measure Your Dog for a Harness

A harness can only work as intended when it fits properly. Breed and weight can help narrow the options, but body shape varies too much for either one to replace actual measurements. For the TrailHarness Adventure Harness, chest measurement should be your primary guide.

What you need

• A soft measuring tape
• A few treats
• A standing dog
• A second person if your dog tends to move

If you do not have a soft tape, use a piece of non-stretch string and measure it against a ruler.

Step 1: Measure the chest

Have your dog stand naturally. Wrap the tape around the widest part of the chest, usually just behind the front legs. Keep the tape level around the body. It should touch the coat without squeezing.

Record the measurement in centimetres and measure a second time. Use the larger of the two readings if they differ slightly.

Step 2: Measure the lower neck

Measure around the lower part of the neck where the harness will sit, not high up where a collar normally rests. Again, keep the tape snug without pulling it tight.

Step 3: Compare both measurements

Use chest measurement first, then confirm the neck range also works. If your dog's measurements fall between two size ranges, choose the larger size and use the adjustment points to refine the fit.

Breed examples are only rough starting points. A Labrador and a Golden Retriever can wear different sizes, and two dogs of the same breed can have very different chests.

TrailHarness size ranges

• XS: chest 33–43 cm; neck 25.5–38 cm
• S: chest 43–56 cm; neck 31.5–50 cm
• M: chest 56–69 cm; neck 32.5–52 cm
• L: chest 69–81 cm; neck 39.5–56.5 cm
• XL: chest 81–107 cm; neck 45–77 cm

Check the fit when it arrives

Put the harness on indoors before removing tags or taking it outside. Adjust the straps evenly so the harness sits centred. You should generally be able to slide two fingers beneath the straps without forcing them.

A good fit should

• Stay centred while your dog walks and turns
• Sit clear of the front-leg movement
• Avoid rubbing in the armpit area
• Remain secure when gentle pressure is applied
• Allow normal breathing, sitting, and lying down

Readjust if you notice

• The harness rotates around the body
• The chest panel rides up toward the throat
• Straps hang loose or gape away from the body
• Hair is pinched or skin is rubbed
• Your dog can back out of the harness

Recheck over time

Puppies, growing dogs, dogs with changing coats, and dogs whose weight changes should be measured again. Inspect the fit before longer outings and after adjusting any strap.

A few careful minutes with a measuring tape can prevent most sizing problems. When in doubt, contact TrailHarness with your dog's chest and neck measurements before ordering.