The number-one reason a harness fails, whether your dog slips out, it rubs, or they refuse to walk, usually is not the harness. It is the measurements. Picture clipping the leash, taking two steps, and watching your dog reverse straight out of a too-loose harness like a furry escape artist. A five-minute measuring session prevents all of that. Here is exactly how to do it.
What you will need
- A soft fabric tape measure, or a piece of string and a ruler
- A treat or two to keep your dog still and happy
- Your harness brand's size chart, since sizes vary between makers
The two measurements that matter
1. Chest girth (the most important)
Wrap the tape around the widest part of your dog's chest, just behind the front legs. Keep it snug but not tight. This number is what most harness sizes are based on.
2. Neck or base girth
Measure around the base of the neck where a collar would sit, low and close to the shoulders. Some harness styles use this measurement too.
Write both numbers down, and note your dog's weight, since many charts list a weight range as a backup guide.
Adjustable at multiple points for a dialed-in fit, a forgiving choice if your dog is between sizes.
Shop nowHow to use the size chart
- Match your chest girth to the chart first, since it is the key number.
- If your dog falls between two sizes, size up, then tighten the straps to fit.
- Double-check against the weight range as a sanity check.
- For puppies, buy adjustable and re-measure every few weeks.
The two-finger test
Once the harness is on, you should be able to slide two fingers flat between the strap and your dog, snug enough it will not slip off, loose enough it never digs in. If you cannot fit two fingers, loosen it. If it slides around, tighten it.
A lightweight step-in vest that is easy to size on wiggly dogs, and it comes with a matching leash.
Shop nowCommon sizing mistakes
- Measuring over a thick coat, so measure on bare fur or account for winter layers.
- Guessing by breed, since two dogs of the same breed can be sizes apart.
- Pulling the tape too tight, when you want a comfortable, natural fit.
- Never re-checking, even though dogs gain weight and puppies grow.
Fully adjustable and breathable for warmer walks, a flexible fit for small dogs and cats alike.
Shop nowOnce it fits
With the right measurements, putting the harness on is the easy part. Here is our companion step-by-step guide to putting on a dog harness. Ready to shop? Explore all of our dog harnesses and everything for dogs. Every order helps support shelter dogs on their way to a forever home.