To find your belly putter, you must do some measuring. The following instructions and the illustration will help you find the right length and lie.
1) First, align your eyes directly over the ball in a comfortable, relaxed stance.
2) Second, determine where you are going to anchor the butt of the shaft on your belly. Most people use their belly button as an anchor point. Once you are in a comfortable, relaxed stance with your eyes directly over the ball, measure the distance from your anchor point to the ball. This measurement will determine the length of the shaft for your belly putter.
3) To get the lie angle, use a protractor to measure the angle of the shaft coming out of the putter head.
Hope this helps in help you find the right belly putter!