Last updated: 2026-06-29

Climbing Grade Conversion

Climbing grade systems are the shared language climbers use to communicate difficulty. Because different regions developed their own scales independently, a route rated 5.11a in California, 6c in France, and VIII in the German-speaking Alps describes the same physical challenge — just through different lenses. This converter maps between the three main rope-climbing scales (YDS, French, UIAA) and the two main bouldering scales (V-scale and Fontainebleau).

Rope climbing grades

Rope climbing grades measure the difficulty of the hardest move on a continuous sequence of climbing protected by anchors. The three scales in common use worldwide are:

Yosemite Decimal System (YDS)

The YDS was developed in the 1950s at Yosemite and remains the dominant scale in North America. The rock-climbing portion spans 5.0 to 5.15, where the decimal sub-grades (a, b, c, d) were added later to subdivide the increasingly crowded upper end. A 5.10a is noticeably easier than 5.10d despite sharing the same whole number, and routes below 5.9 are sometimes written without a sub-grade letter.

French sport-climbing scale

Developed alongside the sport-climbing boom of the 1980s, the French system is the de facto international standard for bolted sport routes. Grades run from 3 through 9c+, using letters (a, b, c) with optional plus signs to subdivide each number. The scale is open-ended — as the world's best climbers push higher, new grades appear at the top.

UIAA scale

The International Mountaineering and Climbing Federation (UIAA) scale uses Roman numerals and is common in central Europe, particularly Germany, Austria, and Switzerland. It runs from I through XIII and uses minus and plus signs to fine-tune difficulty within each Roman numeral band. Unlike the French system, the UIAA scale retains a strong association with traditional mountain routes.

Bouldering grades

Bouldering is climbing on short, unroped problems — typically under five metres — where difficulty comes from a compact sequence of powerful or technical moves. Bouldering grades are independent of rope-climbing grades.

V-scale (Hueco scale)

Developed by John Sherman at Hueco Tanks, Texas, the V-scale runs from V0 (beginner) to V17 (world-class). A V-easy or VB designation is sometimes used for introductory problems, but this converter covers V0–V16 where the Fontainebleau correspondence is well-established.

Fontainebleau bouldering scale

The Fontainebleau scale, named for the boulders south of Paris that hosted early bouldering pioneers, is the European standard. Grades run from 3 to 9A, using capital letters and plus signs (e.g. 7A, 7A+, 7B, 7B+). The capital letters distinguish bouldering grades from the lowercase letters of the rope-climbing scale.

How correspondences work

Grade tables map one system's grades to another by assigning each difficulty level a shared row index. The correspondences are based on widely-used conversion tables published by climbing federations and community resources; the exact mapping varies slightly between sources because grades are assigned by humans and reflect consensus rather than a strict formula.

For example, an intermediate rope climber progressing in North America might be climbing 5.11a. Using the converter:

A bouldering example at a comparable difficulty level:

Grades are approximate

Every grade conversion is an approximation. Rock climbing grades depend on route style — a thin-slab 5.11a at one crag can feel nothing like a powerful overhanging 5.11a at another. Grades represent community consensus on difficulty and can vary by half a grade or more between climbers, areas, and guidebooks. The same principle applies to equivalences across systems: a French 6c is roughly YDS 5.11a, but the "roughly" carries real weight.

Use this converter as a planning reference — for reading foreign guidebooks, comparing performance across regions, or understanding where a target route sits in an unfamiliar system — rather than a definitive statement of absolute difficulty.