Two languages, one boulder
The V-scale (Hueco) is what indoor gyms and US media use. Fontainebleau grades (4, 5, 6a, 6b, 7a…) are what UK outdoor guides and Bleau itself use. Neither is a unit of measurement. Both are opinions that got written down.
Rough conversion
- VB–V0 ≈ Font 3–4
- V1–V2 ≈ Font 5–5+
- V3–V4 ≈ Font 6a–6b
- V5–V6 ≈ Font 6c–7a
- V7–V8 ≈ Font 7a+–7b+
- V9–V10 ≈ Font 7c–8a
Grit at a given Font grade is often “harder” than indoor plastic at the same V-grade because the holds are worse, the feet are worse, and the rock doesn’t care about your board PB.
How to use this
Pick a range, not a number. If you climb indoor V4, start on Font 5+ / 6a outdoors and work up. Sandbagging is a UK tradition. That’s not a bug.