Does the On Cloudrunner 3 Men's run true to size? Should you size up?
We checked, on 8,016 real feet. We worked out the inside measurements of the On Cloudrunner 3 Men's in the standard width: the length, the width, and the forefoot volume (ball girth). Then we virtually fitted 8,016 real feet from our earlier in-store 3D foot scanners, the way a runner shopping online would: On's size chart for length.
On size guide score
63/100
On's size guidance online gave the right size for 63% of 8,016 feet.
Does the On Cloudrunner 3 Men's run true to size?
Yes, for about 6 in 10 feet. If you follow On's size guidance online, the Cloudrunner 3 Men's fits true to size for 63% of feet. Here, true to size means the size On's online guidance gives you is less than a full size away from the size that fits best, with enough toe room and enough forefoot volume.
On's US product page for the Cloudrunner 3 Men's says "True to size," and On's US size chart converts US sizes to other countries' sizes but lists no foot length. For our fittings, we used the Japanese sizes in On's chart as foot lengths, because Japanese shoe sizes are defined by foot length in centimeters. On makes a wide version of the Cloudrunner 3 Men's, but On's size guidance online gives shoppers no way to find out whether they need the wide version, so our score uses only the standard width. If On's guidance showed shoppers how to pick between standard and wide, the score would have been 76.
Should you size up or down in the On Cloudrunner 3 Men's?
The On Cloudrunner 3 Men's fits very similar to the On Cloudtilt in forefoot volume, so the results are the same as the Cloudtilt's. When the writer of this page tried both on, the two shoes also felt similar around the forefoot. The two shoes have different lacing, so the fit over the top of the foot (the instep) may feel different from person to person, and the laces can be adjusted for that. Here is where every foot landed in the Cloudrunner 3 Men's, in the standard width, when we followed On's size chart.
Following On's size guidance online
- Right size from the size chart63%
- Sized up for more forefoot volume26%
- Sized up for toe room only10%
- Sized down for less forefoot volume1%
Share of 8,016 feet. Each foot is counted once.
- Right size from the size chart: 63% of feet got a size that fit both their foot length and their forefoot volume in the standard width. On's size chart worked well for this group in the Cloudrunner 3 Men's.
- Sized up for more forefoot volume: For 26% of feet, the standard width had too little forefoot volume at the size the chart gave. In the standard width, going up a size was the only way to get more forefoot volume, and the bigger size also adds length in front of the toes. The wide version adds forefoot volume and keeps the length, if you already know you need a wide width.
- Sized up for toe room only: 10% of feet had enough forefoot volume, but the length the chart gave left their toes very little room. If your foot is near the long end of your size on On's chart, consider half a size up in the Cloudrunner 3 Men's.
- Sized down for less forefoot volume: For 1% of feet, the standard width had too much forefoot volume at the size the chart gave. The Cloudrunner 3 Men's has no narrow version, so a smaller size was the only way to get less forefoot volume, with less room in front of the toes.
How we measured
We measured the standard width of the Cloudrunner 3 Men's and virtually fitted 8,016 real feet from our earlier in-store 3D foot scanners. Out of 17,311 foot scans, those 8,016 feet fall in the size range of the Cloudrunner 3 Men's (US men's 7 to 14). For every foot, we followed On's size guidance: the length chart, using the Japanese sizes in On's US size chart as foot lengths, in the standard width. The score of 76 with the width options is estimated from standard width steps, not measured on the wide version itself. A difference of a full size or more between On's size and the size that fits best counts as a miss. These numbers show how the Cloudrunner 3 Men's fits a large group of feet, not how the shoe feels on a run.



