What does 6a mean in climbing?
6a is a French sport grade for a roped route. A capital 6A is a Font grade for a boulder problem, and 6a is also a British technical grade, the second half of a trad grade. Same characters, three different scales. Checked 29 October 2026.
French 6a: a roped route
French grades rate roped climbs. In order of difficulty, 6a is easier than 6a+, which is easier than 6b. The BMC says this is the system you will find on lead climbs, top-ropes and autobelays at UK walls. The letter is lower case.
Font 6A: a boulder problem
Font grades rate boulder problems, and the BMC says to note the capital letter: Font grades are always a capital letter (6A) and sport grades are lower case (6a). A 6A boulder problem and a 6a route are different climbs, and there is no reliable conversion between boulder grades and route grades; the app does not convert between them either.
British 6a: half of a trad grade
A UK trad grade has two parts. The technical grade is the second part, and the BMC lists the technical grades as 4a, 4b, 4c, 5a, 5b, 5c, 6a, 6b, 6c, 7a and 7b. It marks the hardest move on the climb, not the whole climb. See the UK trad grade page for how the two parts read together.
Source
- British Mountaineering Council, Indoor climbing grades explained: https://www.thebmc.co.uk/en/indoor-climbing-grades-explained
- British Mountaineering Council, A brief explanation of UK traditional climbing grades: https://www.thebmc.co.uk/en/a-brief-explanation-of-uk-traditional-climbing-grades
- The Summit Social app, its grade converter, read in the app's code on 29 October 2026
For all six grade systems side by side, see climbing grades explained.