Oh I dunno. I just know you can put in what you lifted and how many times and it'll calculate your 1 RM.
"Somewhere, someone isn't impressed by your looks. Not all men jump through the hoops of your fire. You're unbelievably boring to more people than you'll ever know." --Henry Rollins
"If someone tells you something is easy and they can't explain how to do it, it's not easy." --Steve Shaw