space to leave on my sdhc

i will like to know how much space should a leave in my sdhc for de sav files for the games .right now i have like 80 games on my 4 g sdhc.THANKS

Save files are usually only 512KB. Your games are 65-256MB (MB = roughly 1000KB)
So, 100 save files would only be around 51MB. The same size as a small game.You really don't have to worry about save game space. You'll fill your card up with games before you run out of space for the save files. If you really want to, just keep at least 100MB free.