The UIAA scale: climbing grades in Roman numerals

The oldest of the five scales — and the only one in Roman numerals

When you meet a “VII−” on a wall, or a “V+” in the topo of a multi-pitch route, you are reading the UIAA scale. It is named after the international federation of alpine clubs, comes from mountaineering and is considerably older than sport climbing, where it is now mostly superseded by the French scale.

Its history is the history of a scale that was declared finished three times and climbed past three times. Anyone who knows that also understands why no scale in use today still has an end.

It began the wrong way round — in the mountains near Vienna

The first known grading system in climbing comes from an Austrian. Fritz Benesch, born in 1868 in Mißlitz in Moravia, a doctor of law and until 1902 a librarian at the University of Vienna, opened up Vienna’s local mountains Rax and Schneeberg and published a “comparative ranking of routes by their difficulty” in 1894.

It had seven levels and ran in the opposite direction: level VII was the easiest, level I the hardest. That seems illogical today, but it follows the logic of a ranking — first place is the top one, not the bottom.

The snag showed up immediately. Because the hardest was already called level I, there was no room left at the top. When harder ascents were made, the scale had to be extended past zero: first level 0, then 00. Those then-extreme ascents correspond today to roughly the fourth to fifth UIAA grade — that is, to what hangs in the lower range of many gyms. No other detail shows so clearly how little a grade says about the route and how much about the era in which it was given.

Dülfer, Welzenbach and the reversal

In 1913 Hans Dülfer presented a five-level scale that did without numerals and named the difficulty in words: easy, moderately difficult, difficult, very difficult, extremely difficult. It too did not last long — the leap in alpine standards forced an extension upwards.

In 1923 Willo Welzenbach, a German mountaineer and civil engineer, presented a new six-level scale. His decisive intervention was less the number of levels than the direction: from then on the larger number stood for the harder route. What seems self-evident to us today is a decision made in 1923.

Welzenbach himself did not live to see his scale’s career. He died on Nanga Parbat in 1934, at the age of 34.

From the alpine scale to the UIAA scale

In 1947 a six-level alpine scale was drawn up in Chamonix and established itself internationally. From it came the federation’s official scale — with Roman numerals from I to VI, supplemented by “+” and “−”.

The sources diverge on the year of that renaming. On its own page the UIAA writes that the Welzenbach scale officially became the “UIAA scale” in 1967; the standard German-language account names 1968. One year’s difference changes nothing about the substance, but it is a good example of the state of the sources on climbing grades — and a reason why both figures appear on this page rather than one.

The sixth grade was meant to be the end

The scale ended at VI. Not because nothing else could be imagined, but because that grade was regarded as the limit of what was humanly possible. It was only opened after climbers had long left that limit behind in practice.

Here too the sources contradict each other. The German-language account names the years 1977 to 1979 for the opening at the top; the English-language account and the UIAA name 1978 for the introduction of the seventh grade and 1985 for the point at which the open scale was formally adopted. Both versions describe the same delay: climbing practice came first, the scale followed.

The UIAA itself now records the result of that experience unmistakably: its page lists grades up to XI and states in one short sentence that the scale is open. Comparison tables now go up to XII+; nothing at that top end has so far been confirmed by a second ascent.

What the individual grades mean

Unlike the French scale and the Yosemite Decimal System, the UIAA scale has written-out definitions. They come from mountaineering and therefore speak of protection spacing, belay stances and exposure — of things, in other words, that play no part in a gym.

What is remarkable is where these descriptions stop. Up to VII it is possible to say what defines a grade; from VIII the source only states that a verbal definition is not possible. So the scale describes exactly up to the point at which it was originally meant to end — above that it merely keeps counting.

Roman, Arabic, plus and minus

The UIAA and the alpine clubs write their grades in Roman numerals. In everyday use, and especially in gyms, Arabic numerals are widespread: “7−” instead of “VII−”. That is not a different scale, but the same one in a shorter notation.

Refinement happens with “+” and “−”, the English-language account noting that these suffixes are only used from grade III upwards — in easy terrain the distinction would be meaningless anyway. One numeral thus becomes three steps: VII−, VII, VII+. If a route sits exactly on the boundary, intermediate values such as VII+/VIII− are also common.

One confusion is worth knowing about: the Saxon scale in the Elbe Sandstone Mountains also uses Roman numerals, but subdivides from grade VII upwards with the lower-case letters a, b and c. A “VIIa” is therefore not a UIAA grade but a grade from a separate system with its own rules.

Coarser than the French scale

The UIAA scale is not more precise than the others, and in some places it is coarser: there are steps of the French scale to which the comparison tables assign no UIAA grade of their own. A converter that nevertheless produces a single value there is rounding — and selling a rounding as a result.

At such points the converter on this site instead names both neighbouring grades, and for every UIAA grade the Arabic notation as well. Which grade corresponds to which is set out there in full — in the climbing grade converter and deliberately not here, because two tables on the same subject can only drift apart.

Where you meet the scale today

The UIAA scale is used above all in Germany, Austria, Switzerland, the Czech Republic, Slovakia and Hungary. Its real home is alpine multi-pitch routes: there it gives the climbing difficulty of individual pitches, while the grade for the route as a whole comes from a different system.

In sport climbing, by contrast, it is losing ground. Areas with an international public label routes in French as well, or exclusively. There is a historical core to that: on its own page the UIAA concedes that the introduction of separate national scales was a reaction to it initially not recognising developments in rock climbing. The closed sixth grade paved the way for the systems that replaced it.

Frequently asked questions

What do plus and minus after a UIAA grade mean?

They subdivide the grade more finely. V becomes V−, V and V+, and the scale gains three times as many steps without needing new numerals. This fine gradation already existed when the scale officially became the UIAA scale. In addition, intermediate values such as VII+/VIII− are common when a route sits exactly on the boundary between two steps.

Why does my gym display “7−” instead of “VII−”?

That is the same scale in a different notation. The UIAA and the alpine clubs give their grades in Roman numerals; in everyday use Arabic numerals are widespread because they are shorter and easier to read. VII− and 7− denote the same grade. The climbing grade converter on this site shows both notations for every UIAA grade, so that the match stays unambiguous.

Why did the UIAA scale used to stop at the sixth grade?

Because the sixth grade was regarded as the limit of what was humanly possible. The scale was designed as a closed one and had to be opened after climbers had long since exceeded that grade in practice. The sources differ on when that happened: the German-language account names the years 1977 to 1979, while the UIAA itself and the English-language account name 1978 for the seventh grade and 1985 for the formally open scale. All agree that the opening lagged behind climbing practice.

Is the UIAA scale more precise than the French one?

No, in places it is even coarser. In the comparison tables there are steps of the French scale for which no UIAA grade of its own is given. That is why the climbing grade converter shows not a single value there but the two neighbouring grades. That is not a weakness of the converter but a property of the scale: a range claims exactly as much as the table supports.

Where is the UIAA scale still used today?

Above all in German-speaking and Central European countries — Germany, Austria, Switzerland, the Czech Republic, Slovakia and Hungary are named. Its real home is alpine multi-pitch routes, where it gives the climbing difficulty of individual pitches. In sport climbing, by contrast, it is increasingly supplemented or replaced by the French scale, especially in areas with an international public.

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