Short answer: measure the widest part of your dog's chest, just behind the front legs, with a soft tape measure. Use that number to pick the size. If you land between two sizes, size up and adjust the straps.
What you need
A soft tape measure. No tape? Use a piece of string, mark it, and measure the string with a ruler.
Step by step
- Chest (girth). Wrap the tape around the widest part of the chest, right behind the front legs. Keep it snug, not tight.
- Neck. Measure where a collar sits, at the base of the neck.
- Check twice. Dogs wiggle. Measure two times and use the larger number.
- Pick by chest first. The chest decides the size; the neck just has to fall inside the range.
Size chart for our tactical harness
| Size | Neck | Chest |
|---|---|---|
| S | 14.2–17.7 in | 16.9–23.6 in |
| M | 16.5–23.2 in | 19.7–32.3 in |
| L | 17.7–24.4 in | 20.9–36.2 in |
| XL | 21.7–29.9 in | 26.4–43.3 in |
This chart is for the Tactical No-Pull Dog Harness. Other harnesses fit differently, so always use the chart for the exact model you buy.
The two-finger check
Once it's on, slide two fingers under each strap. If they don't fit, loosen it. If there's much more room, tighten it. Walk a few steps and check that it doesn't twist or slide toward the neck.
Common mistakes
- Measuring the waist instead of the chest.
- Picking a size by weight or breed alone.
- Pulling the tape so tight it digs into the fur.
FAQ
What if my dog is between sizes?
Size up. Straps can be tightened; a harness that's too small can't be stretched.
What if I still get it wrong?
For our harness, the size exchange is free within 30 days of delivery (unused, one exchange per harness). We cover shipping both ways.
Can I measure a puppy?
Yes, but puppies grow fast. Plan to measure again every few weeks. Our harness starts at a 16.9 in chest (size S), so it's not for small puppies or toy breeds.