Measure your dog’s girth, around the widest part of the rib cage just behind the front legs, and match it to the chart for the harness you’re buying. Ruffwear, PetSafe and Hurtta each size differently.
Type the girth into the harness and collar size calculator for all three makers’ sizes at once.
How to measure
Ruffwear says to wrap the tape around the widest part of the rib cage, usually the chest right behind the front legs. Hurtta calls the chest the key measurement for a harness, and its Seeker Harness also has a neck range, measured at the base of the neck.
Ruffwear Front Range Harness
| Size | Girth (in) | Girth (cm) |
|---|---|---|
| XXS | 13–17 | 33–43 |
| XS | 17–22 | 43–56 |
| S | 22–27 | 56–69 |
| M | 27–32 | 69–81 |
| L/XL | 32–42 | 81–107 |
Ruffwear says to choose the larger size when your dog is in between. Its general chart for harnesses, apparel and packs splits the biggest sizes into L (32–36 in) and XL (36–42 in), and adds an XXXS (9–13 in) for its Hi & Light Harness.
PetSafe Easy Walk Harness
| Size | Girth | Chest width | Approximate weight |
|---|---|---|---|
| Petite | 12–17 | 7–8 | Under 10 lb |
| Petite/Small | 13–18 | 8–9 | 10–15 lb |
| Small | 15–21 | 9–12 | 15–25 lb |
| Small/Medium | 19–26 | 11–13 | 20–30 lb |
| Medium | 22–32 | 12–15 | 25–50 lb |
| Medium/Large | 24–34 | 14–18 | 40–65 lb |
| Large | 27–40 | 16–21 | 65–95 lb |
| Extra Large | 32–49 | 17–24 | 90+ lb |
PetSafe says measuring is the most accurate way to size the Easy Walk, its weights are only approximate, and a dog between two sizes should go a size up.
Hurtta Seeker Harness
| Size | Chest | Neck |
|---|---|---|
| 35-45 | 13–17.7 in (33–45 cm) | 7.9–11.8 in (20–30 cm) |
| 40-50 | 15–19.7 in (38–50 cm) | 9.8–13.8 in (25–35 cm) |
| 45-60 | 16.9–23.6 in (43–60 cm) | 11.8–17.7 in (30–45 cm) |
| 55-70 | 20.9–27.6 in (53–70 cm) | 13.8–17.7 in (35–45 cm) |
Hurtta’s sizes overlap, so a dog’s chest can fit two of them. Check the neck range as well before you choose.
How snug
PetSafe’s fitting guide asks for a snug fit, with room for only one or two fingers between a strap and your dog. Check the fit again as a puppy grows.