| Used in | United States |
| Range | Class 1–5; Class 5 splits 5.0–5.15 |
| Rates | Hiking, scrambling, and rock climbing |
| Difficulty | Beginner |
Developed at the Sierra Club and refined in California's Yosemite Valley, hence the name.
The Yosemite Decimal System (YDS) is the rating scale used in the United States to describe how difficult terrain is to travel, from flat walking to hard rock climbing. It runs through five classes; Class 5 covers technical roped climbing and is subdivided with decimals from 5.0 up to 5.15 for increasing difficulty.
The system grew out of the Sierra Club’s grading and was refined in Yosemite Valley.
How the scale works
Classes 1–4 span walking, hiking, and exposed scrambling. Class 5 is technical climbing and is where the familiar decimals appear: 5.0 is easy, 5.10 is intermediate, and elite climbs reach 5.15. From 5.10 up, letters (a–d) add precision.
Convert between systems
The US is one of several grading regions. To translate a YDS grade into French, UIAA, or V-scale bouldering grades, use our climbing grade converter, or read the full grade conversion guide.
Good to know
YDS rates the hardest single move or section, not sustained effort or danger — a separate ‘R/X’ protection rating describes how risky the falls are.
Frequently asked questions
How does the Yosemite Decimal System work?
It divides terrain into five classes: 1 is walking, 2–3 is steeper hiking and easy scrambling, 4 is exposed scrambling where many use a rope, and 5 is technical climbing. Class 5 is then split by decimals — 5.6, 5.10, 5.13 — with higher numbers meaning harder climbing.
What does 5.10 mean in climbing?
5.10 is a Class 5 technical climb of moderate-to-hard difficulty. From 5.10 upward, grades add letters (5.10a to 5.10d) for finer distinction. It marks roughly where climbing moves from beginner-friendly into intermediate terrain.
How do US grades compare to French grades?
YDS and the French sport-grade system measure the same difficulty with different scales — for example 5.10a is close to French 6a. Use our climbing grade converter to translate between YDS, French, UIAA, and bouldering scales.
Sources
- Grading systems overview — American Alpine Club