Climbing scales explained: UIAA, Fontainebleau, V-Grade & Co.

Climbing is international—but the rating of routes and bouldering is anything but uniform. Depending on the region and discipline, there are different scales that often define difficulty levels in very unique ways.

Whether UIAA, French, YDS, Fontainebleau (Fb), V-Grade, British Trad, or Scandinavian: Each grading system has its origins, logic, and scope. We've examined the different systems to give you an overview.

Sport climbing

1. UIAA scale

The UIAA (Union Internationale des Associations d'Alpinisme) scale is used primarily in German-speaking countries for rating sport climbing routes on rock. The UIAA scale is also popular in climbing gyms. It rates the most technically difficult section of the route, regardless of the total length or protection. It is represented by Arabic numerals, which can be further enhanced or degraded with a plus or minus.

• Type: Sport climbing
• Region: Germany, Austria, Switzerland, Europe
• Scale: Arabic numerals & optional + or –
• For example: 4, 4+, 5-, 5, 5+
• special feature: Only evaluates the crux, not the overall difficulty

2. French scale (international sport climbing)

The French scale is the global standard in sport climbing. It rates the average difficulty over the entire route—including endurance, readability, and technical variety. Additional letters allow for more steps than the UIAA scale. Unlike the UIAA scale, the French scale sometimes awards an additional plus, but not a minus.

• Type: Sport climbing
• Region: France, worldwide
• Scale: Arabic numbers & letters (a, b, c) & optional +
• For example: 6a, 6b+, 7c, 8a+
• special feature: Considered to be finely graded and intuitively understandable

3. Yosemite Decimal System (YDS) – USA

The Yosemite Decimal System (YDS) is the American equivalent of the French scale in sport climbing. The YDS was first established in Yosemite Valley in the 1950s and quickly spread across North America. It consists of three components: grade, difficulty, and a further gradation of difficulty introduced later.

The YDS originally originated in mountaineering and is structured in decimal notation: Classes 1 and 2 of the system refer to hiking or trail running, Class 3 describes moderately challenging mountain tours, and Class 4 is considered an "intermediate" level for more demanding mountaineering. Sport climbing begins at Class 5. Within Class 5, increasing decimal digits indicate the increasing difficulty of the routes. Starting at the 5.10 level, letters from a to d are added, providing further subdivisions: 5.10a, for example, is easier than 5.10d, followed by 5.11a, and so on.

• Type: Sport climbing, trad climbing
• Region: USA, Canada
• Scale: 5. & Number (0-15) & Letter from grade 5.10 (a–d)
• For example: 5.6, 5.10a, 5.12c, 5.15b
• special feature: International relevance due to famous areas such as Yosemite or Red River Gorge

4. British Trad-Grade – Special case Great Britain

The British trad grading system is unique because it combines two scales: the "Adjectival Grade" (now primarily E-Grade), a comprehensive assessment of the difficulty of the route, including technical requirements, protection, endurance, mental toughness, and rock quality, and the "Technical Grade," which assesses the technical demands of the most difficult move. This combination provides a unique way to determine the character of a route. 

The modern scale starts at E1 (easy extreme range) and is theoretically open-ended (currently around E11/E12 for the hardest routes). A route with a low technical grade can therefore still have a high E grade if it is poorly protected and thus psychologically challenging. A route with a high technical grade can have a comparatively low E grade if it is very well protected. Climbers in the United Kingdom have traditionally placed importance on this distinction—and on traditional climbing in general, which enjoys a special status in the British scene.

• Type: trad climbing
• Region: Great Britain
• Scale:
  • Adjectival Grade: traditional: Modd, Diff, D, VD, S, HS, VS, HVS; modern: E1–E12
  • Technical Grade: 4a–7a
• For example: E5 6a, HVS 5a, E9 6c
• special feature: Evaluates not only technology, but also risks and overall impact

5. Scandinavian scale (Norway, Sweden, Finland)

The Scandinavian scale is widespread throughout much of Northern and Eastern Europe. It is roughly based on the UIAA logic and has no upper limit. It is used in sport and alpine climbing. A distinction is made between the Finnish and the Swedish/Norwegian Scandinavian scale. 

• Type: Sport climbing & alpine climbing
• Region: Scandinavia
• Scale: Arabic numerals & optional + or –
• For example: 5-, 6, 7+, 9-
• special feature: Smooth transitions, no letters like in the French system

Are there differences between climbing and bouldering scales?

In short: Yes. In sport or trad climbing, several components are taken into account: In addition to technical challenge and strength, the climbing scales also assess the endurance required by a route, how difficult it is to place or clip in intermediate anchors, and the mental demand.

Bouldering, on the other hand, is mostly about short, intense sequences of movements: a few moves that require high maximum strength, precision, or even explosiveness. Essentially, bouldering scales only evaluate the crux, i.e., the most difficult single move or the hardest sequence of the boulder. The most important difficulty scales for bouldering are the Fontainebleau and the V scale.

bouldering

6. Fontainebleau Scale (Fb) – Bouldering in Europe

The Fontainebleau scale originates from the forest of the same name south of Paris, one of the most popular bouldering areas in the world. Today, it is the European standard for grading bouldering, both outdoors and indoors. Like the French sport climbing scale, an optional plus can be awarded.

• Type: bouldering
• Region: France, Europe, international
• Scale: Numbers with capital letters & optional +
• For example: 5A, 6C+, 7A, 8B+
• special feature: Evaluates not only individual moves, but the boulder as a whole

7. V-Grade – Bouldering in the USA

The V-System was developed in the USA and takes its name from climber John "Vermin" Sherman. It is the US standard for bouldering and is increasingly being used worldwide – especially in gyms with international guests.

• Type: bouldering
• Region: USA, internationally distributed
• Scale: V0 to V17 (open upwards)
• For example: V2, V5, V10, V15
• special feature: no letters, only numbers

What scale applies in the hall? 

Most climbing gyms use the French scale because it's internationally understandable and well-graded. However, in Germany, Austria, and Switzerland, the UIAA scale is often also used.

Bouldering gyms in Europe occasionally use the Fontainebleau or V-scale, but predominantly use numbers or color markings to indicate the difficulty of a boulder. The color markings actually originate from Fontainebleau, where parkour bouldering was invented.

However, we encounter the Fb and V scales again on training boards such as the Moonboard or the Kilterboard. 

Am I weaker on rock? Indoor scales explained

In the climbing hall, an 8- is no problem, but on the rock, a 7 is almost impossible – it can't be the same difficulty! Yes, it is. It's perfectly normal not to climb to the same grade on the rock as in the gym. In the gym, holds are clearly defined and color-coded. You can immediately see what you can hold or step on. The bolters also make sure that the moves are doable for almost every height and span. On the rock, holds are harder to identify; they're sometimes uneven or smooth. Many things feel unclear or awkward until you find the right solution. It's all about trial and error!

In general, especially in bouldering gyms, bouldering problems are often rated somewhat softer to make them more accessible. Depending on the area, more traditional grades are often given on rock. For example, a 6C in Fontainebleau can feel significantly harder than a 6C boulder in a gym.

How difficult are the levels?

All climbing and bouldering scales have one thing in common: they are open-ended. It can get progressively harder, progressively further, progressively more extreme. The currently most difficult route in the world is Silence 9c (5.15d in the Yosemite Decimal System) in Flatanger, Norway, first ascended by Adam Ondra. So far, no one has managed to repeat Silence, but until then, it remains the benchmark for absolute peak performance in sport climbing.

What's important in all the discussion about difficulty levels is that, in the end, a number is a guide, and every body, and therefore every climbing experience, is unique. Grades only help with classification; movement, focus, and adventure should take precedence over the difficulty of a route. 

You might be interested in:

• Bouldering on rock: How to behave correctly
• The first 9A+? Adam Ondra attempts Fontainebleau's toughest project

Credits: All images Adobe Stock