Convert climbing grades across route and bouldering systems with separate lookup tables, approximate equivalents, and clear discipline-specific context.
How Climbing Grade Conversion Works
Climbing grades are ordered scales, not measurements with a universal equation. The calculator first finds the selected grade’s row in a discipline-specific comparison table and then reads across that row. Route grades stay within the route table, while bouldering grades stay within the bouldering table.
target grade = comparison table[source grade row][target system]
Every result is approximate. A route’s angle, hold type, length, protection, exposure, and local grading tradition can change how hard it feels. British trad grades also include seriousness, so they do not map neatly to sport-climbing systems. A converted value is useful for orientation, but it is not a safety rating or a promise that two climbs will feel identical.
Route Grade Reference
The calculator contains a longer ordered lookup. These representative rows show how YDS, French sport, UIAA, Ewbank, and British trad are kept aligned in the route workflow.
| YDS | French | UIAA | Ewbank | British trad |
|---|---|---|---|---|
| 5.8 | 5a | V+ | 14 | HVS 5a |
| 5.10a | 5c | VI | 17 | E1/E2 5b |
| 5.11d | 7a | VIII | 24 | E5 6b |
| 5.12d | 7c | IX | 27 | E7 6c |
| 5.14d | 9a | XI | 35 | E11 7c |
Bouldering Grade Reference
Bouldering uses a separate lookup because short problems and roped routes test different combinations of movement difficulty, power, endurance, and risk. The route-effort field is contextual only and should not be interpreted as a direct performance prediction.
| V-Scale | Font | Approximate route-move context | Level label |
|---|---|---|---|
| V0 | 4 | 5.10a/b | Beginner |
| V3 | 6A/6A+ | 5.11d to 5.12a | Intermediate |
| V6 | 7A | 5.13a | Advanced |
| V9 | 7C | 5.13d to 5.14a | Expert |
| V13 to V17 | 8B to 9A | Elite route-move range | Elite |
Example Conversions
For a French 7a route, choose Route grade conversions, select French sport, and select 7a. The aligned row reports approximately YDS 5.11d, UIAA VIII, Ewbank 24, and British E5 6b. The result also shows adjacent grades in the selected source system so the position on that scale is clear.
For a Font 7A boulder, choose Boulder grade conversion, select Fontainebleau, and select 7A. The aligned bouldering row reports approximately V6. That says the two labels occupy a similar place in their bouldering scales; it does not predict route endurance or certify a climber’s ability on a particular problem.
Why Two Charts Can Disagree
Grade conversion charts can differ by a partial grade because the underlying systems developed in different regions and climbing styles. Local guidebooks and gyms may also apply their own conventions. When planning a climb, treat the calculator’s result as the center of a small comparison range and consult the route description, local guidebook, and current conditions.
Frequently Asked Questions
Does a converted grade guarantee equivalent difficulty?
No. It is an approximate scale comparison. Technique, style, route length, protection, and conditions can dominate the experience.
Can I convert a route grade directly to a boulder grade?
The calculator deliberately keeps those disciplines separate. Its bouldering table includes route-move context only as a broad explanation, not as a cross-discipline prediction.
Sources
- International Climbing and Mountaineering Federation — Scales of Difficulty in Climbing, current scale overview.
- Draper and colleagues — Comparative grading scales, statistical analyses, climber descriptors and ability grouping: International Rock Climbing Research Association position statement, 2016.
- British Mountaineering Council — Indoor Climbing Grades Explained, current guidance.