How can I measure body fat?

How can I measure body fat percentage without calipers?(Preferably an easy way) What body fat percentage is needed for good looking abs?

Public Comments

1. you can buy scales that measure bodyfat ,muscle mass, water oh yes your weight as well. http://www.argos.co.uk/static/Product/partNumber/8326016/Trail/searchtext%3EBODYFAT+SCALES.htm