Calculate climbing grade conversions across YDS, French, UIAA, British, Ewbank, V-Scale, and Font, with difficulty level and next-grade targets.
Climbing Grade Conversion Formula
Climbing grades do not convert through an equation. Each grading system is an ordered ladder of difficulty, so conversion works by lining the ladders up side by side and reading across a comparison chart:
G_t = C[i][t], i = rank(G_s, s)
Variables:
- G_s is the grade you enter, written in the source system s
- rank( ) locates that grade’s row i on the shared difficulty ladder
- C is the comparison chart, with one row per difficulty step and one column per grading system
- G_t is the equivalent grade read from column t, the system you convert to
The calculator applies this lookup in two modes. Route mode converts a roped-climbing grade across the five major systems: YDS (the American 5.x scale), French sport, UIAA, Ewbank (used in Australia and New Zealand), and British trad. Boulder mode converts between the American V-Scale and the Fontainebleau scale, and adds an approximate route-grade effort comparison. Both modes also report a difficulty level and grade context, meaning the next grade up and the next grade down in your own system, which gives you a concrete progression target after the conversion.
Grade Comparison Charts and Typical Progression
The table below is the full route ladder the calculator reads from. It follows the alignment used by the large European route databases, anchored by consensus benchmark climbs such as Action Directe (9a = 5.14d) and Realization (9a+ = 5.15a).
| YDS (USA) | French | UIAA | Ewbank | British | Level |
|---|---|---|---|---|---|
| 5.0-5.1 | 1-2 | I-II | 6 | M | Beginner |
| 5.2 | 2 | II | 8 | D | Beginner |
| 5.3 | 3 | III | 9 | VD | Beginner |
| 5.4 | 3+ | III+ | 10 | S 4a | Beginner |
| 5.5 | 4a | IV | 11 | HS 4a | Beginner |
| 5.6 | 4b | IV+ | 12 | HS 4b | Beginner |
| 5.7 | 4c | V | 13 | VS 4c | Beginner |
| 5.8 | 5a | V+ | 14 | HVS 5a | Intermediate |
| 5.9 | 5b | VI- | 16 | E1 5b | Intermediate |
| 5.10a | 5c | VI | 17 | E1/E2 5b | Intermediate |
| 5.10b | 6a | VI+ | 18 | E2 5c | Intermediate |
| 5.10c | 6a+ | VII- | 19 | E2/E3 5c | Intermediate |
| 5.10d | 6b | VII | 20 | E3 5c | Intermediate |
| 5.11a | 6b+ | VII+ | 21 | E3/E4 6a | Advanced |
| 5.11b | 6c | VII+ | 22 | E4 6a | Advanced |
| 5.11c | 6c+ | VIII- | 23 | E4/E5 6a | Advanced |
| 5.11d | 7a | VIII | 24 | E5 6b | Advanced |
| 5.12a | 7a+ | VIII+ | 25 | E5/E6 6b | Advanced |
| 5.12b | 7b | VIII+ | 26 | E6 6b | Advanced |
| 5.12c | 7b+ | IX- | 26 | E6/E7 6c | Advanced |
| 5.12d | 7c | IX | 27 | E7 6c | Advanced |
| 5.13a | 7c+ | IX+ | 28 | E7/E8 6c | Expert |
| 5.13b | 8a | IX+ | 29 | E8 7a | Expert |
| 5.13c | 8a+ | X- | 30 | E8/E9 7a | Expert |
| 5.13d | 8b | X | 31 | E9 7a | Expert |
| 5.14a | 8b+ | X+ | 32 | E9/E10 7b | Expert |
| 5.14b | 8c | X+ | 33 | E10 7b | Expert |
| 5.14c | 8c+ | XI- | 34 | E10/E11 7b | Elite |
| 5.14d | 9a | XI | 35 | E11 7c | Elite |
| 5.15a | 9a+ | XI+ | 36 | E11/E12 7c | Elite |
| 5.15b | 9b | XI+ | 37 | E12 7c | Elite |
| 5.15c | 9b+ | XII- | 38 | E12+ | Elite |
| 5.15d | 9c | XII | 39 | E12+ | Elite |
Not every published chart matches this one, and the disagreement is systematic rather than random. Many American charts pin 5.10a to French 6a, while European databases and most professional climbing media pin 5.10a to 5c and 5.10b to 6a. The two families drift apart by about one letter grade between 5.9 and 5.11a and converge again at the elite end, where famous benchmark routes force agreement. If a conversion looks half a grade off from your gym chart or guidebook, this is why. Treat any converted grade as the middle of a small range rather than an exact value. British grades add a second complication: the E number rises with danger as well as difficulty, so a bold but physically moderate route can carry a higher E grade than a safe, harder sport climb.
The bouldering table adds two columns you will not find on a standard conversion chart: an approximate route-grade effort comparison and a typical time to reach each grade with consistent climbing two to three times per week. The time benchmarks are rough medians, and age, climbing background, and training quality move them a lot in both directions.
| V-Scale | Font | Approx. Route Effort | Level | Typical Time to Reach |
|---|---|---|---|---|
| VB | 3-4 | 5.7 to 5.9 (4c-5b) | Beginner | First session |
| V0 | 4 | 5.10a/b (5c-6a) | Beginner | First weeks |
| V0+ | 4+ | 5.10c (6a+) | Beginner | 1 to 3 months |
| V1 | 5 | 5.10d to 5.11a (6b/6b+) | Beginner | 1 to 3 months |
| V2 | 5+ | 5.11b/c (6c/6c+) | Intermediate | 3 to 6 months |
| V3 | 6A/6A+ | 5.11d to 5.12a (7a/7a+) | Intermediate | 6 to 12 months |
| V4 | 6B/6B+ | 5.12b (7b) | Intermediate | 1 to 2 years |
| V5 | 6C/6C+ | 5.12c/d (7b+/7c) | Advanced | 1.5 to 3 years |
| V6 | 7A | 5.13a (7c+) | Advanced | 2 to 4 years |
| V7 | 7A+ | 5.13b (8a) | Advanced | 3 to 5 years |
| V8 | 7B/7B+ | 5.13c/d (8a+/8b) | Advanced | 4 to 6 years |
| V9 | 7C | 5.13d to 5.14a (8b/8b+) | Expert | 5+ years |
| V10 | 7C+ | 5.14a/b (8b+/8c) | Expert | 6+ years, structured training |
| V11 to V12 | 8A to 8A+ | 5.14b to 5.14d (8c to 9a) | Expert | Many years of dedicated, structured training |
| V13 to V17 | 8B to 9A | 5.14d to 5.15d+ (9a to 9c+) | Elite | Professional level; a small fraction of climbers ever reach it |
Climbing Grade Conversion Examples
Example 1: French sport to YDS. You redpoint 7a and want the American equivalent. Select route mode, choose French sport as the source system, and pick 7a. The 7a row of the chart reads 5.11d in YDS, VIII in UIAA, 24 in Ewbank, and E5 6b in British trad, with a difficulty level of Advanced. The grade context line shows 7a+ as the next goal grade and 6c+ as one grade easier.
Example 2: Font boulder to V-Scale. A gym problem is tagged 7A on the Font scale. Select boulder mode, choose Fontainebleau, and pick 7A. The result is V6 on the V-Scale, an approximate route effort of 5.13a (7c+), and a difficulty level of Advanced. The effort figure means the hardest moves compare with the crux of a 5.13a route, not that a V6 boulderer has the endurance to send a 5.13a route.
FAQ
Are climbing grade conversions exact?
No. Each system was developed independently, in a different climbing area and style, so the ladders do not line up perfectly. A conversion is reliable to within about half a grade in the middle of the scale and tighter at the elite end, where repeated ascents of famous routes have forced consensus. British trad grades are the loosest fit because the E number also encodes danger and seriousness, which the other systems ignore.
Is a V4 boulder as hard as a 5.12b route?
Move for move, roughly yes: the crux of a 5.12b typically involves climbing at about V4 intensity. But a boulder problem is a handful of moves off the ground, while a route stacks many sequences on top of each other and adds pump, clipping, and route reading. A dedicated V4 boulderer usually needs months of endurance work before redpointing 5.12b, and a 5.12b route climber may struggle on a V4 that suits a boulderer perfectly.
Why does my gym feel softer or harder than this chart?
Gym grades are set by routesetters calibrating to their own community, and most commercial gyms drift soft by a half grade to a full grade compared with outdoor consensus, especially below V5 or 5.12. Some training-focused gyms drift the other way. The chart reflects outdoor consensus grading, so use it to compare between systems, and expect your first outdoor climbs to feel harder than the same number in the gym.
