Matt's right on that... skinfold techniques sometimes cannot give an accurate measurement of visceral body fat. Calculating body fat via caliper method is still one of the most inaccurate methods available, even if you perform it utilizing the 7-site method, which is believed to be the most accurate skinfold method. I've read studies that concluded a stand deviation of +-10% body fat alone. I do not recommended it unless you've had formal training. And it is definitely not recommended that you perform on yourself because it is extremely difficult to get an accurate measurement that way.
Not sure of your reasons for to trying to find body fat percentage, but if it is just for normal in-home use, I'd go with a good bioelectrical impedance body fat scale (unless you have anything akin to a pace maker). But don't go cheap on them as they get less and less accurate the more cheaply they are made. To get a good reading that does not fluctuate, it is best to weigh yourself at the same time every day when your water content is the most uniform between days... normally first thing in the morning, as increased water in the system can cause a lower reading than what is actually true.
