i find many 1 rep max calculators misleading and as they usually involve continuous reps its difficult to compare when i nearly always do sets of singles. Anyway today i did 324.5pds x 15 singles on deadlift what would my max be roughly?
This doesn't really tell us anything. Someone with a 400 lb. DL could do 15 singles with 325, but so could someone with a 700 lb. DL.
Work up to a heavy single and you will have a better idea.