Climbing grades: understanding every system (French, Font, V-scale, YDS, UIAA)

This article goes through the 5 grading scales used in climbing around the world, tells where they come from, gives the reference conversion table and explains why a grade isn’t quite the same thing as perceived difficulty. By the end, you’ll be able to read a Norwegian topo, a Hueco Tanks guidebook or a Frankenjura leaflet without wondering whether you’re setting off at your level or 3 grades above it.

Where grades come from

The Roman numeral scale you use today comes from Willo Welzenbach, who codified it in the 1920s with 6 degrees, VI set as the limit of what a human could do. The UIAA (Union Internationale des Associations d’Alpinisme) only made it official in 1967, still closed at the top. It opened up because the rock had moved ahead of it: Reinhold Messner challenged the limit in The Seventh Grade (1973), Reinhard Karl and Helmut Kiene put up the Pumprisse at the Wilder Kaiser on 2 June 1977 and dared to grade it VII, and the UIAA ratified the 7th degree in 1978 before making the scale open-ended at the top in 1985.

In France, in the 1970s, the first ascensionists of the Verdon, Buoux and the Saussois moved to a system in Arabic numerals (3, 4, 5, 6…) completed by the letters a, b, c and the + sign to subdivide each degree. This system, finer than the UIAA one, became the reference for sport climbing in Europe.

At Fontainebleau, because people have been climbing ropeless on short boulders since the start of the 20th century, a dedicated scale took hold, separate from the route one.

In the United States, 2 separate scales developed on their own: the YDS for routes, the V-scale for bouldering.

The French system: routes and Fontainebleau bouldering

France actually uses 2 separate scales that look very much alike. For routes (sport or multi-pitch), the scale runs from 1 to 9c in lower case: 6a, 6a+, 6b, 6b+, 6c, 6c+, 7a… For bouldering, the Fontainebleau scale uses the same graduations but in upper case: 6A, 6A+, 6B… up to 9A at the moment (Burden of Dreams, the 1st 9A).

The subdivision rule is the same in both cases. Between 2 full grades (7a and 7b, say), you slot in a half grade (7a+). Between a full grade and its half grade (between 7a and 7a+), you can still split it in two with a slash grade: 7a/7a+. The tags “soft” and “hard” say that a route is easy or hard for its grade without moving it up or down a notch.

A few benchmark routes: Galaxy at Céüse (7b+) is still the historic benchmark for the grade. La Rose et le Vampire at Buoux (8b), first ascended by Antoine Le Menestrel in 1985, served as the world reference for 8b for a long time. Bibliographie at Céüse (9b+), freed by Alex Megos in August 2020 at 9c then downgraded to 9b+ by Stefano Ghisolfi in 2021, shows how fragile grades get at the extreme end. Silence at Flatanger, in Norway (9c), first ascended by Adam Ondra in September 2017, is the first 9c ever proposed.

The V-scale system (USA, bouldering)

The V-scale was born at Hueco Tanks, Texas, driven by John Sherman, nicknamed Vermin. In 1991 he put forward an open-ended scale starting at V0 for what matched European 5+/6a bouldering at the time, going up in full grade increments: V0, V1, V2… with no a/b/c subdivisions. The only subdivision allowed is the + (V5+, V6+…).

The V-scale took hold in North America, Oceania and Japan. Today the top end is V17: Burden of Dreams in Finland (Lappnor, first ascended by Nalle Hukkataival in 2016, repeated by Will Bosi in 2023, Simon Lorenzi in 2024 then Aidan Roberts in May 2024, Return of the Sleepwalker in Nevada (first ascended by Daniel Woods in March 2021)…

The YDS system (USA, routes)

The YDS, or Yosemite Decimal System, comes from a classification developed by the Sierra Club in the 1930s to describe mountain terrain as a whole. Classes 1 to 4 cover walking, off-trail hiking, steep ground where you need your hands and easy unbelayed climbing. Class 5 means climbing that needs a rope.

Class 5 subdivides from 5.0 (the easiest) up to 5.15d today. From 5.10 on, each grade is subdivided into a, b, c, d. So 5.10a is easier than 5.10d, which is itself easier than 5.11a. One quirk: you don’t say “five point ten a” but “five ten a”, as if the 5 were the category and the 10a the grade.

The YDS also builds in a seriousness element, inherited from trad and multi-pitch, in the form of the R and X suffixes, detailed further down.

The UIAA system

The UIAA scale, in Roman numerals from I to XII (with the + and – variants), is still alive in German-speaking countries: Germany (Frankenjura, Elbsandstein), Austria, German-speaking Switzerland, northern Italy (Dolomites). You’ll come across it in alpine multi-pitch topos and in Czech topos.

Quick markers: UIAA VI+ matches French 6a, VIII matches 7a, X matches 8b and XI matches 9a. Beyond XII the scale stays open, but it’s barely used any more for modern high-end grades, which switch to French or YDS.

Full conversion table

The table below cross-references the 3 main scales for routes (French, YDS, UIAA, plus Font bouldering and the V-scale in a separate column as a reminder of equivalent effort). No boulder/route conversion is mathematical. The equivalence rests on the fact that, for the same pure physical difficulty, a boulder problem is graded on average 3 to 4 grades higher than the same section built into a route (because the boulder concentrates the whole effort into a few moves).

French route	YDS (USA route)	UIAA	French boulder (Font)	V-scale (USA boulder)
4	5.6	IV	3	VB
5a	5.7	V-	4-	VB
5b	5.8	V+	4	V0-
5c	5.9	VI	4+	V0
6a	5.10a	VI+	5	V1
6a+	5.10b	VII-	5+	V2
6b	5.10c	VII	6A	V3
6b+	5.10d	VII+	6A+	V3
6c	5.11a	VII+/VIII-	6B	V4
6c+	5.11b	VIII-	6B+	V4
7a	5.11c	VIII	6C	V5
7a+	5.12a	VIII+	6C+	V5
7b	5.12b	VIII+/IX-	7A	V6
7b+	5.12c	IX-	7A+	V7
7c	5.12d	IX	7B	V8
7c+	5.13a	IX+	7B+	V8
8a	5.13b	IX+/X-	7C	V9
8a+	5.13c	X-	7C+	V10
8b	5.13d	X	8A	V11
8b+	5.14a	X+	8A+	V12
8c	5.14b	XI-	8B	V13
8c+	5.14c	XI-/XI	8B+	V14
9a	5.14d	XI	8C	V15
9a+	5.15a	XI/XI+	8C+	V16
9b	5.15b	XI+/XII-	9A	V17
9b+	5.15c	XII-	(9A+)	(V18)
9c	5.15d	XII	(9B)	(V19)

The cells in brackets flag theoretical grades, not yet confirmed by a repeated, consensual ascent. The boulder/route conversion on a given row is not a strict physical equals sign: an 8A boulder doesn’t “turn into” 8b on a route, it’s just the comparable order of magnitude of effort when the boulder is built into a long endurance route.

A grade and perceived difficulty are not the same thing

A grade is meant to measure the objective difficulty of a sequence. What goes into it are measurable physical parameters: size and shape of the holds, spacing of the holds, orientation of the holds (facing up, sidepulls, underclings), angle of the wall, length of the wall, position and number of the clips.

What doesn’t go into the grade, in theory: how you feel on the day, the friction (temperature, humidity), the beta you pick (the best beta often downgrades routes), whatever morphological handicap you may have on that particular route (a tall climber can pull a move at full stretch, a short one has to jump for it), your emotional attachment to the grade.

Didier Delignières (INSEP, 1991, La difficulté en escalade : proposition d’une approche psychophysique) showed that there is no linearity between perceived effort and actual effort. When the effort is well below what you’re capable of, you struggle to tell 2 easy grades finely apart. When you get close to your maximum, one extra scrap of difficulty feels insurmountable. Practical upshot: you grade most accurately in your “moderate comfort” zone, meaning routes that are middling hard for you, not too hard, not too easy.

That’s also why a 6a in the gym can feel very different from a 6a on rock. Worth digging into in the indoor vs outdoor grades article.

Slash grades and the morpho debate

On some routes it’s near impossible to settle between 2 grades. The difficulty lands right on the hinge. Climbers in good shape feel the lower grade, those in worse shape the higher one. Hence the slash grade (7a/7a+, 8b+/8c).

In late June 2025, Kimbrough Moore, a climber and philosophy professor at the University of San Francisco, published an essay that stirred up the community. His thesis: the system is skewed by its historic yardstick (an adult man of about 1.75 m) and should shift to systematic multiple grades according to body size (7a/6c+, for instance, to mean “7a for a small climber, 6c+ for a tall one on a reachy move”). The idea: a grade rates the human experience that rubs up against the rock more than it rates the bit of rock itself.

Bill Ramsey, another climbing philosopher, from Nevada, answered him shortly after in Rethinking Slash Grades. The opposite argument: multiplying grades according to body types would create an illusion of precision and destroy the universality of the system. Comparing 2 routes with each other would get absurdly complicated. For Ramsey, better to accept that a grade is a useful approximation than to try to fragment it endlessly.

The debate isn’t settled and keeps doing the rounds in the specialist magazines (Climbing, Gripped, Grimper). It joins older controversies about the downgrading of extreme routes, like Bibliographie or Fred Rouhling’s Akira. To go further into those controversies, see the article downgrades and 9c.

Seriousness, R, X, E: the grade doesn’t tell you everything

In the United States, the YDS builds in a seriousness element. R stands for Runout: the potential fall is long but probably not lethal. X means a fall can kill you (ground, ledge, bolt too far away). These letters go after the technical grade: a 5.11a X is physically within reach for a 6c+ climber, but a mistake won’t be forgiven.

In the UK, trad combines 2 grades on every route, and would deserve an article of its own. The E-grade (E1, E2… E11 today) conveys the overall seriousness, which mixes physical difficulty, quality of the protection and potential fall height. The tech grade (4a, 5b, 6c…) conveys the pure technical difficulty of the hardest move. It’s the most honest system for describing climbing where you place the protection as you go and where pure physical difficulty isn’t enough to describe the route. Technically, an E1 5a and an E5 5a climb the same. What changes is the nerve: the E5 asks for 10 times more.

In French sport climbing, the grade stays purely physical. Seriousness doesn’t show up in the number. It’s down to the topo and to word of mouth to flag the run-out pitches, the serious finishes or the high first bolts.

Working out a grade finely: the triplet method

If you want to grade a route you’ve just put up or compare 2 sequences, the so-called triplet method suggests cutting the route into short sections (5 to 10 moves, graded like a Font boulder in upper case) and long sections (beyond 15 moves, graded like a route in lower case), separated by rests rated G (good), M (medium), B (bad), N (none).

The reference equivalence: a boulder problem before a resistance section adds about +3.3 grades to the route, a boulder problem after a resistance section adds about +5 grades. A readable example: La Rage de Vivre at Buoux (8b+) = 8b G 8a+. Silence at Flatanger (9c) = 8b G 8C M 8B B 7C+ G 7A.

For the detail of the route grading system and the benchmark routes, see the dedicated article: climbing route grades.

FAQ

What grade should you start climbing at?

It depends above all on the physical condition you start from and on how easy you are with movement. Broadly, in the gym, an adult beginner usually climbs in the 4s and 5s during the first sessions, then moves into 5+ very quickly and reaches the 6th degree within a few weeks or months of regular practice. On well-bolted sport crags, aiming for routes graded 4 to 5b for the first trips is a good marker. 6a is often seen as the first real technical barrier. To structure your progression, see progressing in climbing.

Is a 6a in the gym the same as a 6a on rock?

No. Commercial gyms tend to grade “generously” to keep their customers coming back. A gym 6a often matches a 5c on rock, especially at historic crags (Saussois, Buoux, Annot). Moving from resin to limestone or granite also adds a difficulty of reading the rock and of footwork that the gym doesn’t reproduce. Covered in depth in indoor vs outdoor grades.

How do you convert from V (USA) to Font?

Quick markers: V3 = 6A, V5 = 6C, V7 = 7A+, V9 = 7C, V11 = 8A, V13 = 8B, V15 = 8C, V17 = 9A. The V-scale is less finely grained than Font (no a/b/c), so several Font grades land on the same V grade. Full table and explanations in bouldering grades.

To go further… keep reading