What size harness do you need?

Do you know what harness you need? Make sure that you measure your dog’s neck, chest, and height to determine what will fit best. Use our calculator to help give you an idea of what’s needed.







dog harness

How to measure for a harness

You need two measurements, and a soft tape measure makes life much easier. First, the chest girth: wrap the tape around the deepest part of the ribcage, just behind the front legs. This is the measurement that matters most. Second, the neck: measure around the base of the neck where a collar would naturally sit, not up high behind the ears. Measure snugly but not tight, and if your dog is between sizes, size up. A treat held at nose height keeps most dogs standing still long enough to get it done, and if your floof finds the tape measure suspicious, let them sniff it first and reward calm behaviour. Handling practice like this is also great groundwork for stress-free vet visits.

Getting the fit right

Once the harness is on, use the two-finger rule: you should be able to slide two fingers comfortably under every strap. Any looser and your dog may wriggle out; any tighter and it will rub, especially behind the front legs where chafing is most common. Check that the harness does not sit across the shoulder joints in a way that restricts the front legs, and re-check the fit every few months, since coat changes, weight changes and general wear all affect it. We are big fans of harnesses over collars for walking, particularly for dogs who pull, as they spread pressure across the chest rather than the throat. Pair a well-fitted harness with the advice in our walking on and off the lead guide and walks get better for everyone.

FAQ

  • For attaching the lead, a harness is kinder, especially for pullers, small breeds and flat-faced breeds, because it avoids pressure on the throat. A flat collar is still useful for carrying an ID tag, which is a legal requirement for dogs in public in the UK.

  • Snug enough that it cannot slip over the head or shoulders, loose enough to fit two fingers under every strap. Watch for rubbed or thinning fur behind the front legs, which is the classic sign of a poor fit.

  • Go slowly and pair every step with treats: reward for looking at the harness, then for a nose through the head loop, then for a clip done up. A few short sessions of this beats a daily wrestling match, and it is exactly the kind of positive reinforcement we bang on about across the whole site.