Hand to shaft ratio 

form of measurement;

Comparison of shaft length and hand-size in a formula for measurement of penis size;
the relationship in quantity, amount, or size between a penis shaft and the hand gripping it;
the quantitative relation between a penis and a hand;

the relationship in quantity, amount, or size between a penis and a hand.

He said he's a solid 8 inches and sent you a picture? Did you use the hand to shaft ratio to determine if this is true?

If you go off of the fact that "a hand" is a form of measurement, based on the width of a grown man's hand, understood to equal 4 inches, you can use the hand to shaft ratio to determine the object size at hand.

Hand to shaft ratio by MareBare84 September 23, 2014