How hard is a 5.9 climb?
5.9 is a roped climb in the American YDS, and it is the last grade before the letters start at 5.10. In The Summit Social's grade table it is level 6 of 17, beside French 5a and British technical 4c. Other charts place it a little higher, so read any match as rough. Checked 29 October 2026.
What the number means
The 5 in 5.9 is the YDS class for technical roped free climbing. The number after the point counts up with difficulty, from 5.0 to 5.9. From 5.10 the system adds the letters a, b, c and d, as in 5.10a.
The number is about the hardest move on the route. On trad routes a protection rating (G, PG, R or X) can follow it.
Where it sits in the app
The app's grade table runs from level 1 to level 17. Level 6 holds YDS 5.9, French 5a and British technical 4c.
Other charts differ
No conversion is exact. Mountain Project's comparison table places 5.9 beside French 5c and British HVS 5a, a step or two above the app's table. The app's table is the one the app uses; read any chart as a guide.
Source
- Mountain Project, international climbing grades comparison table, read 29 October 2026: https://www.mountainproject.com/international-climbing-grades
- The Summit Social app, its grade table (17 levels) and grade picker, read in the app's code on 29 October 2026
For all six grade systems side by side, see climbing grades explained.