Many climbing routes have grades to calibrate the technical difficulty, and in some cases the risks, of the route to the climber. The first ascensionist can suggest a grade but it will be amended for the 'consensus view' of subsequent ascents. While many countries with a tradition of climbing developed their own grading systems, a small number of grading systems have become internationally dominant for each type of climbing, and which has led to the standardization of grading worldwide. Over the years, grades have consistently risen in all forms of climbing, helped by improvements in climbing technique and equipment.

In free climbing (i.e. climbing rock routes with no aid), the most popular grading systems are the French numerical or sport system (e.g. 7c+), the American YDS system (e.g. 5.13a), and latterly the UIAA scale (e.g. IX+). These systems solely grade the technical difficulty and are used for the lower-risk activity of sport climbing. The American system adds an R/X suffix to calibrate the additional risks of traditional climbing routes. Notable traditional grading-systems include the British E-grade system (e.g. E4 6a).

In bouldering (i.e. rock climbing on short routes), the popular systems are the American V-scale (or "Hueco") system (e.g. V14), and the French "Font" system (e.g. 8C+). The Font system often attaches an "F" prefix to further distinguish it from French sport climbing grades, which itself uses an "f" prefix (e.g. F8C+ vs. f8c+). It is increasingly common for sport-climbing rock-routes to describe their hardest technical movements in terms of their boulder grade (e.g. an f7a sport climbing route being described as having a V6 crux).

In aid climbing (i.e. the opposite of free climbing), the most widely used system is the A-grade system (e.g. A3+), which was recalibrated in the 1990s as the "new wave" system from the legacy A-grade system. For "clean aid climbing" (i.e. aid climbing equipment is used but only where the equipment is temporary and not permanently hammered into the rock), the most common system is the C-system (e.g. C3+). Aid climbing grades take time to stabilize as successive repeats of aid climbing routes can materially reduce the grade.

In ice climbing, the most widely used grading system is the WI ("water ice") system (e.g. WI6) and the identical AI ("alpine ice") system (e.g. AI6). The related sport of mixed climbing (i.e. ice and dry-tool climbing) uses the M-grade system (e.g. M8), with other notable mixed grading systems including the Scottish Winter system (e.g. Grade VII). Pure dry-tooling routes (i.e. ice tools with no ice) use the D-grade prefix (e.g. D8 instead of M8).

In mountaineering and alpine climbing, the complexity of the routes requires several grades to reflect the difficulties of the various rock, ice, and mixed climbing challenges. The International French Adjectival System (IFAS, e.g.TD+) – which is identical to the "UIAA Scale of Overall Difficulty" (e.g. I–VI) – is used to grade the 'overall' risk and difficulty of mountain routes (with the gradient of the snow/ice fields). For example, the 1938 Heckmair Route on the Eiger is graded: ED2 (IFAS), VI− (UIAA), A0 (A-grade), WI4 (WI-grade), 60° slope. Related 'commitment grade' systems include the American National Climbing Classification System (e.g. I–VI).

History

In 1894, the Austrian mountaineer introduced the first known climbing grading system, which he introduced to rock climbing. The "Benesch scale" had seven levels of difficulty, with level VII the easiest and level I the hardest; as more difficult climbs were made, the grades of level 0 and level 00 were added.

In 1923, German mountaineer Willo Welzenbach compressed the scale and reversed the order so level 00 became level IV–V, and it became popular in the Alps. In 1967, the "Welzenbach scale" formally became the "UIAA scale" for rock climbing (or "UIAA Scale of Difficulty") with Roman numerals I–VI, and a "+" and "−" to refine each level. The UIAA also incorporated proposals made in 1943 by and the on a broader "Scale of Global Assessment" for alpine climbing (the French Alpine System), and created the "UIAA Scale of Overall Difficulty" by assigning Roman numerals I–VI to the six adjectival levels (e.g. F, PD, AD, D, TD, and ED) of the French system. The UIAA also incorporated a "Scale of Difficulty in Aided Climbing" for aid routes with the levels: A1, A2, A3, A4, and (later) A5. In 1978, the UIAA added the VII (seventh grade) to its "UIAA scale", implying that the scale was open-ended, a concept formally adopted in 1985.

By the 1980s, French guides had customized the "UIAA scale" beyond V+ with the letters "a", "b", and c" (e.g. V+, VIa, VIb, etc.). At the end of the 1980s, French climbing guidebook author published the "French numerical scale", replacing the UIAA Roman numerals with Arabic numerals, where French 6a equaled UIAA VI+. The two scales were labelled "Plaisir Grades" and aligned in a UIAA table where French grades 1–6a aligned with "UIAA scale" grades I–VI+; beyond that level, the two systems diverged (e.g. French 7a+ equates to UIAA grade VIII and French 9a equates to UIAA grade XI).

In America, a version of the Welzenbach Scale was introduced for rock climbing in 1937 by the Sierra Club, which in the 1950s was further adapted into the Yosemite Decimal System that added a decimal place to the class 5 grade (e.g. 5.2, 5.3, 5.4, etc.), and which by the 1960s was again amended to introduce the letters "a", "b", "c", and "d" after 5.9 to further refine the levels (e.g. 5.9, 5.10a, 5.10b, 5.10c, etc.).

While individual countries developed their own rock climbing grading systems, the American system, French system, and latterly the "UIAA scale" became popular internationally (with the American and French dominating sport climbing). The UIAA "Scale of Overall Assessment" dropped its six Roman numbers in favor of the six adjectival grades of the French Alpine System (to avoid confusion with the "UIAA scale") and dominated alpine climbing grading, while the UIAA "Scale of Difficulty in Aided Climbing" – amended and expanded in Yosemite in the 1990s as "new-wave" grades – dominated aid grading.

Free climbing

Free climbing is a form of rock climbing in which the climber can use their rock-climbing equipment only for their protection, not as an artificial aid to help them in ascending a climbing route. The two main free climbing grading systems (which include the two main free climbing disciplines of sport climbing and traditional climbing) are the "French numerical system" and the "American YDS system". The "UIAA scale" is still popular in Germany and across parts of Central Europe. Many countries with a history of free climbing have also developed their own free climbing grading systems including the British E-grade system and the Australia/New Zealand "Ewbank" system.

The evolution of grade milestones in traditional climbing, and latterly sport climbing (as it took over from traditional climbing as the main focus of the leading free climbers), is an important part of the history of rock climbing. As of May 2026, the hardest free climbs in the world are the handful of sport climbing routes that are graded at 9c (French), 5.15d (American YDS), and XII+ (UIAA), however, none have yet been repeated.

French numerical grade

The French numerical system for free climbing was developed from the UIAA scale in the 1980s but uses Arabic numbers instead of the UIAA scale's Roman numerals, and also uses the letters "a", "b" and "c" and the "+" symbol to give additional refinement between the numbers (whereas the UIAA uses only the "−" and "+" symbols). The French system starts at 1 and closely aligns with the UIAA scale up to UIAA V+, which is French grade 5a, but thereafter begins to diverge. The French grading system is the dominant system in Europe, and it and the American YDS system are the most dominant systems worldwide; beyond the easiest grades, the two systems can be almost exactly aligned in comparison tables.

The French system is an open-ended scale that was at 9c in 2026 with Silence and a handful of others. The system is focused on the technical demands of the hardest movement on the route. Unlike the American YDS system, there is no allowance for any risks, and thus the French system is more closely aligned with sport climbing, where pre-bolted protection removes the risk. It is less common to find traditional climbing routes graded by the French system, and thus it is also called the French sport grade. To avoid confusion between French grades and the British E-grades, a lowercase "f" (for French) is used as a prefix (e.g. f6a+); this should not be confused with the use of the capitalized "F" or "fb" prefix in Font boulder grades.

American YDS grade

The American YDS (or 'Yosemite Decimal System') was developed independently by climbers at Tahquitz Peak who adapted the class 5 rating of Sierra Club Class 1–5 system in the 1950s. The class 5 portion of the class scale is a rock climbing classification system, while classes 1–4 are used for hiking and scrambling. Climbers use class "5" as a prefix, which is then followed by a period and a number that starts at 1 and counts up with increasing difficulty (e.g. 5.4, 5.5, 5.6, etc.). At 5.10, the system adds the letters "a", "b", "c", and "d" as further refinements between levels, and the scale continues upward (e.g. 5.10a, 5.10b, 5.10c, 5.10d, 5.11a, 5.11b, etc.,). The American YDS system is the dominant system in North America, and it and the French numerical system are the most dominant systems worldwide; beyond the easiest grades, they can be exactly aligned.

The American YDS system is an open-ended scale, with the current hardest climb being 5.15d, established by Silence in 2017. Like the French system, the numerical component of the American YDS system is focused on the hardest move on the route. In 1980, Jim Erickson introduced an additional rating for traditional climbing routes where the level and quality of the climbing protection are assessed. A suffix of "PG-13" (using the American cinema classification system) denotes the climbing protection is adequate, and if properly placed a fall will be short (in practice, the "PG-13" is usually omitted as it is considered the default). A suffix of "R" is added where protection is inadequate and any fall could risk serious injury, and "X" for routes with little or no protection and where any fall could be very long and potentially fatal (also known as a "chop route").

American big wall climbing routes will often include the NCCS grade (Levels I–VII) with the YDS grade (e.g. the Salathé Wall at 5.13b VI).

UIAA scale

The UIAA scale (or UIAA Scale of Difficulty) for free climbing was developed from the original "Welzenbach scale" in 1967 and uses the Roman numerals of that scale with "+" and "−" symbols for refinement between numerals after Grade III (i.e. III, IV−, IV, IV+, V−, V, V+ etc.,). Initially, the UIAA scale was closed-ended and went from Grade I (easiest) up to Grade VI (hardest), where it stopped. In 1978, the "seventh grade" was added—though climbers had been climbing at that level for years—and by 1985 it was formally made into an open-ended scale that went beyond Grade VII.

The UIAA scale is closely aligned with the French system up to Grade V+, which is French grade 5a, but thereafter begins to diverge, although the two can be reasonably aligned in comparison tables. The UIAA scale was at XII+ in 2026 with Silence, which is French 9c. While the French system became the dominant scale in Europe, the UIAA scale is still popular in Germany, Austria, Switzerland, Czech Republic, Slovakia, and Hungary. The UIAA scale is also commonly found in the grading systems of alpine climbing routes, and particularly those that use the French Alpine System (e.g. PD, D, TD, ED), where the UIAA scale is often used to grade the free climbing component.

British E-grade