The range spans 2 Ruffwear sizes. Which one you need depends on where your dog sits inside Julius-K9 “0” — which is exactly what a measurement settles.
The dog harness size conversion chart
Every brand’s sizes, lined up against each other on one scale. A Julius-K9 “1” is a Ruffwear “M”. Here is all of it, sourced and dated.
Know one brand’s size? Convert it
Julius-K9 0 fits
58–76 cm
PetSafe Medium covers this whole range on its own — a straight swap.
The range spans 3 Kurgo sizes. Which one you need depends on where your dog sits inside Julius-K9 “0” — which is exactly what a measurement settles.
Blue-9 M covers this whole range on its own — a straight swap.
L and XL both cover this whole range. L (43–85cm) sits most centrally around it, leaving adjustment either way.
Puppia XL covers this whole range on its own — a straight swap.
The range spans 3 PetSafe 3 in 1 sizes. Which one you need depends on where your dog sits inside Julius-K9 “0” — which is exactly what a measurement settles.
The range spans 3 Dog Friendly Co sizes. Which one you need depends on where your dog sits inside Julius-K9 “0” — which is exactly what a measurement settles.
The range spans 4 PawSafe sizes. Which one you need depends on where your dog sits inside Julius-K9 “0” — which is exactly what a measurement settles.
The range spans 3 Wonder Walker sizes. Which one you need depends on where your dog sits inside Julius-K9 “0” — which is exactly what a measurement settles.
The range spans 2 Top Paw sizes. Which one you need depends on where your dog sits inside Julius-K9 “0” — which is exactly what a measurement settles.
A solid chip covers the whole range on its own — a straight swap. A percentage is how much of the range that size covers, so anything under 100% depends on where your dog sits inside it. Measure once and the question disappears. Link to this conversion →
Every size, on one scale
| Chest girth | Julius-K9 | Ruffwear | PetSafe | Kurgo | Blue-9 | Rabbitgoo | Puppia | PetSafe 3 in 1 | Dog Friendly Co | PawSafe | Wonder Walker | Top Paw |
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| 24 cm | — | XXXS | — | — | — | — | — | — | — | — | — | — |
| 26 cm | ||||||||||||
| 28 cm | ||||||||||||
| 30 cm | Baby 1 | X-Small | XS | |||||||||
| 32 cm | Petite | |||||||||||
| 34 cm | XXS | XS | S | X-Small | XX-Small | |||||||
| 36 cm | Baby 2 | Toy | ||||||||||
| 38 cm | ||||||||||||
| 40 cm | Petite/Small | XXS | ||||||||||
| 42 cm | S | X-Small | ||||||||||
| 44 cm | Mini-Mini | XS | Small | Small | M | |||||||
| 46 cm | S | XS | XS | X-Small | — | |||||||
| 48 cm | ||||||||||||
| 50 cm | M | Small | Small | |||||||||
| 52 cm | Mini | Small/Medium | ||||||||||
| 54 cm | Medium | L | S | Small | ||||||||
| 56 cm | — | |||||||||||
| 58 cm | S | |||||||||||
| 60 cm | M | L | S | Medium | ||||||||
| 62 cm | Medium | Medium | M | |||||||||
| 64 cm | 0 | |||||||||||
| 66 cm | Large | XL | ||||||||||
| 68 cm | M | Medium | ||||||||||
| 70 cm | M | XL | — | |||||||||
| 72 cm | 1 | Medium/Large | M/L | L | Large | |||||||
| 74 cm | ||||||||||||
| 76 cm | L | |||||||||||
| 78 cm | Large | |||||||||||
| 80 cm | 2 | Large | ||||||||||
| 82 cm | L | X-Large | — | Large | ||||||||
| 84 cm | L | XL | ||||||||||
| 86 cm | X-Large | |||||||||||
| 88 cm | ||||||||||||
| 90 cm | 3 | XL | X-Large | |||||||||
| 92 cm | XL | |||||||||||
| 94 cm | Extra Large | |||||||||||
| 96 cm | ||||||||||||
| 98 cm | — | |||||||||||
| 100 cm | — | |||||||||||
| 102 cm | ||||||||||||
| 104 cm | — | |||||||||||
| 106 cm | ||||||||||||
| 108 cm | 4 | — | ||||||||||
| 110 cm | — | |||||||||||
| 112 cm | — | — | ||||||||||
| 114 cm | — | |||||||||||
| 116 cm | ||||||||||||
| 118 cm | ||||||||||||
| 120 cm | ||||||||||||
| 122 cm | — | |||||||||||
| 124 cm | ||||||||||||
| 126 cm | — | |||||||||||
| 128 cm | ||||||||||||
| 130 cm | ||||||||||||
| 132 cm | ||||||||||||
| 134 cm | ||||||||||||
| 136 cm | ||||||||||||
| 138 cm |
How to use this
Find your dog’s chest girth in the left column and read across. Every cell is that brand’s own size label for a dog of that measurement. A dash means the brand does not make a harness that size.
Where a brand’s sizes overlap — and they all overlap, deliberately, so the adjustment straps have somewhere to go — the cell names the size your dog sits most centrally in. If you are between two, the sizing tool shows both and where you fall inside each.
Choose a starting size
Open any published size in the converter above to see which sizes overlap at the other brands. The answer stays on this page, and its link keeps your chosen brand and size.
Julius-K9 Baby 1 · Baby 2 · Mini-Mini · Mini · 0 · 1 · 2 · 3 · 4
Ruffwear XXXS · XXS · XS · S · M · L · XL
PetSafe Petite · Petite/Small · Small · Small/Medium · Medium · Medium/Large · Large · Extra Large
Kurgo X-Small · Small · Medium · Large · X-Large
PetSafe 3 in 1 X-Small · Small · Medium · Large
Dog Friendly Co XXS · XS · S · M · L · XL
Wonder Walker Toy · X-Small · Small · Medium · Large · X-Large
Top Paw XX-Small · X-Small · Small · Medium · Large · X-Large
Where these numbers come from
- Julius-K9 — IDC Powerharness, 29–138 cm · source · checked 2026-08-19
- Ruffwear — Harness (girth sizing), 23–107 cm · source · checked 2026-10-04
- PetSafe — Easy Walk Harness, 30.5–124.5 cm · source · checked 2026-08-19
- Kurgo — Tru-Fit Smart Harness, 30–112 cm · source · checked 2026-08-19
- Blue-9 — Balance Harness, 34–110.5 cm · source · checked 2026-08-19
- Rabbitgoo — ControlPro No-Pull Harness, 29.5–96.5 cm · source · checked 2026-08-28
- Puppia — RiteFit Harness, 33–80 cm · source · checked 2026-08-28
- PetSafe 3 in 1 — Easy Walk 3 in 1 Harness, 33–108 cm · source · checked 2026-10-04
- Dog Friendly Co — No-Pull Dog Harness, 39–103 cm · source · checked 2026-10-04
- PawSafe — Steady+Style No Pull Harness, 45.7–111.8 cm · source · checked 2026-10-04
- Wonder Walker — No-Pull Harness, 34.3–121.9 cm · source · checked 2026-10-04
- Top Paw — Mesh Comfort Dog Harness, 33–99.1 cm · source · checked 2026-10-04
Quote this chart anywhere. A link back is appreciated, not required.