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.

Climbing Grade Converter

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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 example:
  YDS 5.11a  |  French 6c   |  UIAA VIII-  |  Ewbank 22
  YDS 5.12a  |  French 7a+  |  UIAA IX-    |  Ewbank 25

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.

Example and notes

Selecting French 7a returns YDS 5.11d, UIAA VIII, and Ewbank 24. Selecting YDS 5.10a returns French 6a+, UIAA VI+, and Ewbank 18.

Tips: treat conversions as a starting point, not a guarantee — local grading culture, rock type, and route style all shift how a grade feels. When travelling, expect a one-sub-grade swing in either direction until you calibrate to the local crag. The table here covers the heart of the sport-climbing range, roughly YDS 5.4 through 5.14, which is where most converted grades are needed.