I just got some Accumeasure Digital fat calipers today at a clearance sale today. I know where to pinch, but exactly how much should I pinch? Should I pinch as hard as I can?
you take a 3 inch fold of skin at the respective sites. I would pinch fairly hard, as you are trying to get a true reading. Also, be sure to pull the fold away from the skin as much as possible.
Really weird... my BF% is coming out to 7.8% whereas on a Tanita BF scale it was 10%. Which one's more accurate?
Both methods will give you a ball park reading. The object is to use the same method the whole time and to track your progress via that method.
There will always be variations between "method A" and "method B" because they rely on different assumptions and different study results to generate the value for %body fat. Joel is correct about using them to track the changes over time. Keep using both methods and see if the variation (about a 2% difference) remains consistent as you increase or decrease your body fat.