Harness & Collar Size Calculator
Find the perfect harness and collar size from a few measurements.
A poorly fitted harness or collar can cause chafing, escape, breathing problems and even tracheal damage in small dogs. This calculator turns your dog's neck and chest measurements into the right size band (XS to XXL) and gives a fit-check rule-of-thumb.
How this calculator works
Sizing is based on the most common manufacturer charts (Ruffwear, Julius-K9, Kurgo). Sizes overlap, so we use both your neck and chest measurement and pick the larger size to avoid pinching. The two-finger rule means you should be able to slide two flat fingers under the strap — no more, no less.
Frequently asked questions
My dog is between sizes — which do I pick?
Always size up. A slightly loose harness can be tightened with the adjusters; a too-tight one can't be loosened.
How often should I re-check size?
Puppies: every 4 weeks. Adult dogs: every 3 months, or after any noticeable weight change.
Is a harness or collar safer for walking?
A Y-shaped front-clip harness is safer for most dogs (especially pullers, brachycephalics and small breeds). Use a flat collar for ID tags only.
Harnesses & collars
