How much do dog harness size charts disagree?
FurPick research · 12 charts, 70 sizes · charts read up to 2026-10-04 · charts maintained by Noureddine M.
A lot. A harness labelled Medium fits a chest of 38–56 cm at Puppia and 69–81 cm at Ruffwear — ranges that do not even touch. One 60 cm dog is a PawSafe XS and a Puppia XL. Across 12 charts from 11 brands, a size label tells you almost nothing until you know whose it is.
The findings
- The same letter is a different dog. For XS, S, M, XL, the smallest and largest versions of the size across brands share no measurement at all.
- One dog, 11 labels. A 63 cm chest is given 11 different size labels by the charts that fit it.
- A size is a band, and bands vary 9-fold. The narrowest size covers 5.1 cm of chest (Top Paw X-Small); the widest covers 45.7 cm (Wonder Walker X-Large). The median is 17.9 cm.
- Most sizes overlap; a few leave gaps. Of 58 neighbouring sizes, 43 overlap, 11 meet exactly, and 4 leave a gap — measurements for which the brand prints no size.
What “Medium” means at each brand
Every chart that prints an M or Medium, smallest to largest, with the chest range the maker gives for it:
Where the charts leave gaps
- Dog Friendly Co: nothing between S (to 61 cm) and M (from 62 cm).
- Top Paw: nothing between X-Small (to 45.7 cm) and Small (from 48.3 cm).
- Top Paw: nothing between Small (to 55.9 cm) and Medium (from 58.4 cm).
- Top Paw: nothing between Medium (to 68.6 cm) and Large (from 71.1 cm).
What it means if you are buying
Never carry a letter from one brand to another — a dog that is a Medium at one maker can be a Small or an X-Large at the next. Measure the chest once, behind the front legs (how), and read the size off each maker’s own chart. The size finder does that for all 12 charts at once, and the converter translates a size you already own.
Method
The data is every size in the 12 harness charts on FurPick, each transcribed from the maker’s own published chart with its source and the date it was read (latest: 2026-10-04). Charts printed only in inches are converted at 2.54 cm to the inch. Letter sizes are grouped across spellings — “X-Small” with “XS”, “Medium” with “M”; combined sizes such as “M/L” and numbered sizes such as Julius-K9’s “0” are kept out of the letter tables but counted in the one-dog figures. A size “covers” a measurement when the measurement falls within its published range, ends included. Every figure on this page is computed from the data when the site is built, so it changes when a chart does. How the charts are read: the method.
Data and citation
The full dataset is free to reuse under CC BY 4.0: download it as JSON or CSV. To cite this page: FurPick, “How much do dog harness size charts disagree?”, furpick.com/research/harness-size-charts-disagree, 2026-10-05.