Climbing Grade Converter
YDS, French and UIAA for routes; V-scale and Font for boulders — type any grade in any scale, with the caveat that conversions are approximate.
Routes — Yosemite Decimal, French sport, UIAA
| YDS (US) | French | UIAA |
|---|---|---|
| 5.5 | 4a | IV |
| 5.6 | 4b | V− |
| 5.7 | 4c | V |
| 5.8 | 5a | V+ |
| 5.9 | 5b | VI− |
| 5.10a | 6a | VI |
| 5.10b | 6a+ | VI+ |
| 5.10c | 6b | VII− |
| 5.10d | 6b+ | VII |
| 5.11a | 6c | VII+ |
| 5.11b | 6c+ | VIII− |
| 5.11c | 7a | VIII− |
| 5.11d | 7a+ | VIII |
| 5.12a | 7b | VIII+ |
| 5.12b | 7b+ | IX− |
| 5.12c | 7b+ | IX− |
| 5.12d | 7c | IX |
| 5.13a | 7c+ | IX+ |
| 5.13b | 8a | X− |
| 5.13c | 8a+ | X |
| 5.13d | 8b | X+ |
| 5.14a | 8b+ | XI− |
| 5.14b | 8c | XI |
| 5.14c | 8c+ | XI+ |
| 5.14d | 9a | XII− |
| 5.15a | 9a+ | XII |
| 5.15b | 9b | XII+ |
| 5.15c | 9b+ | XIII− |
| 5.15d | 9c | XIII |
Bouldering — V-scale and Fontainebleau
| V-scale | Font |
|---|---|
| VB | 3 |
| V0 | 4 |
| V1 | 5 |
| V2 | 5+ |
| V3 | 6A |
| V4 | 6B |
| V5 | 6C |
| V6 | 7A |
| V7 | 7A+ |
| V8 | 7B |
| V9 | 7C |
| V10 | 7C+ |
| V11 | 8A |
| V12 | 8A+ |
| V13 | 8B |
| V14 | 8B+ |
| V15 | 8C |
| V16 | 8C+ |
| V17 | 9A |
These tables are approximations, and honestly so
No two grading systems measure quite the same thing. The French sport scale describes the overall difficulty of a redpoint, the UIAA scale grew out of a different tradition and compresses differently at the top, and the American decimal system carries a letter grade that many European guidebooks simply do not distinguish. Around 5.12 the tables start disagreeing with each other, and every published version differs by a step somewhere.
Style matters more than the number implies. A 5.11 slab, a 5.11 offwidth and a 5.11 steep-and-juggy route can feel two grades apart to the same climber. Local grading conventions vary too, sometimes sharply — a well-known crag's 5.10 can be another's 5.11, and both are being sincere.
Bouldering conversion is looser still. The V-scale and Font scale run at different resolutions in places, so the mapping here is one common alignment rather than a universally agreed one.
Ice — Water Ice scale
WI1 — Low-angle ice. Walkable with crampons; no tools needed.
WI2 — Consistent 60-degree ice with good protection.
WI3 — Sustained 70-degree with places to rest and good screws.
WI4 — Sustained 80-degree, or vertical with rests. The first grade that feels like real ice climbing.
WI5 — Long, strenuous, sustained vertical with few rests and thinner protection.
WI6 — A full rope length of near-vertical to vertical with no rest, or overhanging and technical.
WI7 — Overhanging, thin, or poorly bonded — protection is questionable and falling is not an option.
Mixed — M scale
M1–M3 — Easy mixed ground. Low angle, no tools required for most of it.
M4 — Slabby to vertical with some technical dry tooling.
M5 — Sustained vertical dry tooling.
M6 — Vertical to overhanging with technical tool placements.
M7 — Overhanging and strenuous; ten metres or so of hard climbing.
M8 — Very overhanging, with powerful moves and marginal tool placements.
M9 — Continuously overhanging with body-length dynos between placements.
M10+ — Roofs and horizontal sections. Grades continue upward from here.
Ice and mixed grades do not cross-convert to rock grades and no honest table pretends otherwise. They describe different problems — commitment, protection quality and how much the medium itself can be trusted, none of which the rock scales measure at all.
How to use
- Type a grade in any supported scale.
- Read the approximate equivalents.
- Treat conversions at the top end as looser.
- Expect local variation between areas.
Frequently asked questions
How exact are these conversions?
Approximate, and increasingly so at the top of the scales. The systems were developed independently with different assumptions, so no conversion is exact — most tables agree within a grade at the lower end and disagree more as difficulty rises.
Why do the same grades feel different between areas?
Because grading is consensus among local climbers, and consensus differs. Areas have reputations for being stiff or soft, and a grade at a historic crag frequently reflects the standards of when it was first climbed rather than today's. This is not a flaw so much as how the system works.
What do the YDS letters mean?
From 5.10 upward, American grades subdivide into a, b, c and d, since the difference between the easiest and hardest 5.10 is substantial. Below 5.10 there are no letters, which is why the jump from 5.9 to 5.10a covers a wider band than the numbering suggests.
How do boulder grades relate to route grades?
They do not convert directly, and treating them as equivalent misleads. Boulder grades describe a short sequence of very hard moves; route grades describe sustained difficulty over a pitch. A climber strong at one is not automatically at the equivalent in the other.
What is the difference between V-scale and Font?
V-scale is American and open-ended from V0; Font is French, from Fontainebleau, using numbers with letters and plus signs. They cover the same territory by different conventions, and the correspondence between them is approximate throughout.
Does the grade tell me if a route is safe?
No, and this is the important limitation. Grades describe technical difficulty only. Protection quality, runout, rock quality and commitment are conveyed separately — by an R or X suffix in some systems, by guidebook description in others — and a well-protected hard route can be far safer than an easy poorly protected one.
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