German abbreviation help - abkürzung

In English, we can abbreviate " year old " to y.o. and I do it in my Excel spreadsheets. I am about to finalise an Excel spreadsheet to my firm's management in DE this time and would like to abbreviate Jahre alt if possible and appropriate.

Abbreviation = abkürzung in DE, and I have looked at this site but could not find an equivalent to Jahre alt / years old.

Would anyone know if putting down J.a as an abbreviation for Jahre alt would be appropriate ?

Thanks in advance.

Would it not work if you just used the word "Alter"? Not an Abkürzung, but certainly shorter.

I am trying to label some columns eg 5-8 yo, 17-19 yo and if I went with Alter, would eg 5-8 Alter be appropriate ??

Not really, no. You would use "5-8 Jahre" or "5-8 J.". For lists/colums, you wouldn't normally use "Jahre alt" - you'd use that in a full sentence only.

If you wanted to use Alter, you'd have to say "Alter: 5-8" or "Alter: 5-8 Jahre" (or "... J.").

Or... you can use "Alter" just for the title of the column:

Alter:

1-4 J.

5-8 J.

etc.

Hope that was understandable

I concur with Elle - in a chart header, the abbreviation "x-x J." is correct. "Jahre alt" would normally only be used in a sentence.