Climbing grading systems, and who defines each one.

What a grade is

A technical paper by the Italian Alpine Club (CAI), written by G. Mandelli and A. Angriman of the CAI's Central School of Mountaineering and hosted by the UIAA (undated), explains that grading works by climbers comparing a passage with what they have already climbed. That makes grades subjective and shaped by local habits and conditions, and the paper says a grade should refer to optimal conditions. The UIAA's grades page adds that route length, style, continuity, rock type, protection, exposure and conditions all change how hard a climb feels, and that equivalences between systems are approximate.

The scales at a glance

The example grades show the format of each scale; they are not paired with each other across a row.

The UIAA scale

The UIAA says its scale became the official UIAA scale in 1967, originally running from I to VI with plus and minus refinements. The seventh grade was formally introduced in 1978, and the scale was explicitly opened upward in 1985. The CAI paper says the scale adopted in 1967 was the Welzenbach scale, and calls the 1978 recognition of grade VII late, since many climbers had already climbed harder. Wikipedia traces the system to Fritz Benesch's scale of 1894 and Willo Welzenbach's revision of 1923; those dates are not on the UIAA page and are unconfirmed.

Sources disagree on when the scale became open-ended. The UIAA and the CAI paper say 1985. Several secondary sources, including Wikipedia, give 1979.

The UIAA describes some of its grades in words: V as technical climbing on smaller or less obvious holds, VI as sustained, demanding free climbing, VIII as very small, widely spaced holds that need trained finger strength, and XI as elite difficulty needing highly specialised preparation.

The French scale

The CAI paper says that towards the end of the 1980s Francois Labande, compiler of guidebooks including those to the Dauphine, presented the French scale aligned to the UIAA scale, using Arabic numerals and putting 6a where UIAA VI+ had been. Mammut, a maker, describes the scale in July 2025 as running from 1 to 9c, with letters from grade 5 and plus signs for finer steps. Wikipedia gives the top French grade stated in 2026 as 9c, for the route Silence. The BMC notes that UK climbers who have climbed only sport or indoors tend to use French grades.

The Yosemite Decimal System

The CAI paper says the YDS comes from the Sierra Club system introduced in 1937, refined in the 1950s at Tahquitz Rock, California, by adding a decimal to class 5. Wikipedia dates the Sierra Club system more loosely to the 1930s and credits the decimal subdivision at Tahquitz to Royal Robbins, Don Wilson and Chuck Wilts; the names come from Wikipedia only and are unconfirmed.

The CAI paper says 5.0 corresponds to UIAA III, and that the YDS usually rates only the hardest passage, not the overall difficulty, protection or exposure. Wikipedia says letters a to d are added from 5.10 upward, that the scale currently tops out at 5.15d (also for Silence), and that R and X suffixes can signal risk. The CAI paper adds a historical note: in the early 1970s the American 5.10 was compared to the European grade VII.

British adjectival and technical grades

The BMC describes UK trad grades in two parts: an adjectival grade for overall difficulty, including seriousness, how sustained the climbing is, exposure and rock quality, and a technical grade for the hardest single move. Technical grades run from 4a to 7b in the BMC's list. The BMC says the top E grade is currently E11, while Wikipedia records an E12 given to a route abroad. The trad climbing page has the BMC's typical pairings.

The Ewbank scale

The CAI paper says the Australian scale was born in 1967 from an idea of John Ewbank, who found the English scale then used in Australia had weaknesses. Wikipedia describes it as an open-ended run of whole numbers with no suffixes, used in Australia, New Zealand and South Africa, and says it is meant to factor in exposure, length and rock quality as well as the hardest move.

Other national rock scales

The CAI paper names several other local systems: Saxon (for Elbe sandstone), Scandinavian, Brazilian, South African, Soviet and Bohemian scales, and Swiss "plaisir" grades. It also describes a protection-quality scale used next to technical grades in Italian and Swiss guides: R1 to R6 for removable gear, S1 to S6 for bolts and RS for a mix.

Bouldering grades

Wikipedia credits the V scale to John "Verm" Sherman and his 1991 Hueco Tanks guidebook, and gives V17 (Font 9A) as the top grade stated in 2026. The CAI paper warns that Font grades do not mean the same as route grades written with the same symbols. The bouldering page has the detail.

Ice, mixed and winter grades

The CAI paper describes a two-part ice-fall grade introduced in Europe around 1985, and the letters WI for water ice, AI for alpine ice and M for mixed sections. The BMC describes Scottish winter grades as an overall Roman numeral plus a technical number; it says the scale runs to X, while Wikipedia records grade XII routes. The alpine, ice and mixed page has the detail.

Alpine, commitment and aid grades

• French alpine overall grades run F, PD, AD, D, TD and ED (Wikipedia), each split into "inf." and "sup." (CAI paper).
• NCCS commitment grades in the US run I to VII, from a few hours to many days, according to Wikipedia only, which credits Leigh Ortenburger; unconfirmed.
• Aid grades run A1 to A5, with a "new wave" extension to A6, and C grades when no hammer is needed (Wikipedia). The CAI paper credits Jim Bridwell with an aid table that reflects mental commitment.

Who publishes conversions

The CAI paper notes that the UIAA has produced comparison tables between scales over the years, though few guidebook authors refer to them. The UIAA's current worldwide table is published only as an image on its grades page. Other publishers, including Mountain Project and Mammut, publish their own charts, and they do not all agree. The grade comparison tables page shows each one as published. The site also has a grade comparison tool.