Quick girth assessment. So a quarter is .955 inches, two quarters is 1.91 inches. And geeking it up, using pi, 1.91 inches is the diameter of a circle with a circumference or a girth of 6 inches. So a quick visual for a 6 inch girth is the width of two quarters or the "two quarter test". We all are not that perfectly cylindrical, so it's not a perfect test, but proof of a 6 inch girth is fairly easy with a camera and two quarters out of your change drawer......please anyone else share their test??