Are climbing grade conversions exact?

No. Grading systems describe difficulty differently and were developed in different regions, so conversions are approximate consensus mappings rather than exact equivalences. A route that feels like 6c in France might feel slightly easier or harder once converted to the Yosemite Decimal System.

What is the Yosemite Decimal System (YDS)?

The YDS is the American free-climbing scale. Technical rock difficulty is the fifth class, written as 5.x, from easy 5.0 up to 5.15. From 5.10 onward each number is split into a, b, c, and d sub-grades to give finer resolution at harder levels.

How does the French Sport system work?

French Sport grades run from about 1 to 9, with each number subdivided into a, b, and c, plus an optional plus sign, for example 6a, 6a+, 6b. It is the dominant system for sport climbing in Europe and is widely used internationally on bolted routes.

What is the Australian Ewbank system?

The Ewbank system, used in Australia and New Zealand, is an open-ended single-number scale starting around 1 and currently reaching the high 30s. Unlike YDS or French it uses one number with no letters, so higher numbers simply mean harder climbs.

Why do UIAA grades use Roman numerals?

The UIAA scale, common in Germany, Austria, and Central Europe, traditionally uses Roman numerals with plus and minus modifiers, such as VII+ or VIII-. It maps closely onto the French and YDS scales but reflects the alpine tradition the system grew out of.

What is the Climbing Grade Converter?

Pick a route grade in any system — Yosemite Decimal (YDS), French Sport, UIAA, or Australian Ewbank — and instantly see the equivalent grades in all the other major rock-climbing grading systems side by side. It runs free in your browser on Gera Tools, with nothing uploaded.

Climbing Grade Converter

Name: Climbing Grade Converter
Creator: Gera Tools
License: https://creativecommons.org/licenses/by/4.0/

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Climbing Grade Converter

Rock climbing has no single global grading system — American climbers use the Yosemite Decimal System, Europeans use French Sport or UIAA, and Australians use the Ewbank scale. This converter takes a grade in any of those systems and shows the consensus equivalents across all of them.

How it works

The tool uses a fixed conversion table where each row represents one difficulty level and stores the matching grade in every system. When you pick a source system and grade, the tool finds that row and reads off the other columns:

Row examples:
  YDS 5.10a  |  French 6a+  |  UIAA VI+   |  Ewbank 18
  YDS 5.11a  |  French 6c   |  UIAA VIII- |  Ewbank 22
  YDS 5.12a  |  French 7a+  |  UIAA IX-   |  Ewbank 25
  YDS 5.13a  |  French 7c+  |  UIAA X     |  Ewbank 29

Because the underlying data is a lookup table built from widely published cross-reference charts, no arithmetic conversion is applied — the mappings reflect community consensus rather than a formula, which is the correct approach since the systems are not linearly related.

Understanding each grading system

Yosemite Decimal System (YDS). The American system for free climbing. Class 5 is technical rock requiring a rope; grades run from 5.0 (beginner) to 5.15 (elite). From 5.10 onward, letters a–d subdivide each number: 5.10a is easier than 5.10d. The system was developed in Yosemite and Tahquitz and remains the standard in North America, though the definitions of grades above 5.12 have drifted over time as standards have risen.

French Sport grades. Used throughout Europe and internationally for bolted sport climbing routes. Numbers run from around 3 to 9, with a, b, and c subdivisions plus an optional plus. So the sequence goes: 6a, 6a+, 6b, 6b+, 6c, 6c+, 7a… The system is open-ended and is now used globally for benchmarking hard routes.

UIAA. The International Climbing and Mountaineering Federation scale uses Roman numerals with plus and minus modifiers (V+, VI, VI+, VII−…). It is common in German-speaking countries, Central Europe, and on traditional Alpine routes. The scale maps reasonably well onto French grades, with VII− roughly corresponding to 6a.

Australian Ewbank. An open-ended single-number scale, currently reaching the mid-30s at the extreme end. No sub-grades or letters — just a number. Higher always means harder. Ewbank 18 is accessible to an intermediate climber; the 30s are the domain of elite athletes.

Why conversions are approximate

The systems developed independently in different regions, measuring difficulty through different lenses — the typical gear, rock type, and local consensus all influence how a grade feels. A sustained, crimpy 5.12a in Rifle, Colorado might not feel the same as its French equivalent on a steep limestone overhang. Route style (slab vs. overhang vs. crack), rock friction, and the density of holds all modulate perceived difficulty outside the grade.

When you travel to a new crag, budget for one to two grades of confusion in either direction until you calibrate to the local style. Many climbers find they climb slightly harder on familiar home rock and slightly less on unfamiliar surfaces.