Let's assume you've found the true zero point
. If so, I recall that the espresso setting is somewhere between 4 (ristretto) and 8 (double), depending on the coffee and your personal preferences. I didn't drink much French press in the days I owned a Rocky doserless, but I think 1/3rd turn coarser from the espresso zone is a good starting point if you follow Sweet Maria's Recommendations
That said, it's better to learn by feel what the right grind setting is rather than rely on number swapping. Your question reminds me a good response posted by Jim a few years back in Grinds...but what does it look like
Generally, a quick way to check grinds is to pinch them between your fingers and feel how granular they are:
- Turkish: a powder, like flour.
- Espresso: very fine grained, like 10x sugar
- Drip (fine grind): like fine sand
- Medium Grind (vacuum pots, fast French Press, and cupping): a tad finer than table salt
- Coarse (for slow french press): between table and kosher salt.
You can go to a supermarket, buy some cheap beans, and grind them at the standard setting to get a feel.
For espresso, the grounds should stick together when pinched between your fingers. If they don't, the coffee is either stale or the grind setting is too coarse. Although Jim describes the feel as "10x sugar", I would add that it should feel grainy when you rub it between your fingers. If you don't feel some grainy inconsistency, it's too fine.