How to measure up
It's really easy (and fun!) to measure yourself and find which myONE Perfect Fit size you need to use. First and foremost, make sure you have a firm erection, boner, stiffy, whatever you want to call it. Some guys find it helpful to ask their partner to do the measuring for them.
Okay, let's go. Take out a measuring tape. If you only have a ruler, you can use a piece of paper to measure. Just mark on the paper when measuring your circumference and length, and then use the ruler to measure the paper.
Measure Your Length
Measure your length as you would like the condom to sit on your erection. Most guys measure along the top-side of their erection, from the pubic hair to the very tip (helmet).
Measure Your Width/Girth
Wrap the measuring tape gently, not tightly, around the thickest part of your erection. If you'd like, you can also take several measurements along your shaft and calculate the average.