At what compression ratio do you need to start using higher octane?

We figured that my compression ration is about 12-12.5to 1. Is that to a point where i'd need more than 87 octane? If not, what is? Thanks again guys!
Jake

12:1 compression with iron heads would be ROUGH even on premium pump gas.

LSx series can pull it off...barely.
Mine is running 11:1 and requires premium.
When it was 10.1:1 it required premium.

If your compression ratio is that high, you should think about replacing the pistons with dished or something to lower it unless you want to run 110 octane or higher...