Anyone knows how to match the grade and the opus?

Thanks

I don't think it is that simple. I am certainly not aware of any existing catalogue (e.g. like Eleanor Baillie's book on Chopin). Czerny produced a lot of opus numbers so my generalizations might be way off mark, and many of them - certainly the collections of studies that I know - are big works containing many pieces that vary greatly in difficulty:

e.g. Op 299 - 40 pieces, Op 740 - 50 pieces, Op 821 - 160 pieces (Exercises)

These are all quite advanced. I'd say the easiest of them are suitable for Grade 4 or 5 and the most difficult would challenge a professional concert pianist. Each one focuses on a particular technique so the way to use them is to pick the right ones for the skills that neeed to be developed or re-inforced.Op 740 has a thematic table of contents to help with selection.

Have I missed the point of your question? Which Opus numbers do you have in mind? Are you interested in his studies, in his other works, or both?

Sorry, maybe my question confuse you.

What I meant is, the order of the opus according to the difficulties.

Thanks.