You should have paid more attention to your math teacher when she tried to explain π to you. It is a beneficial tool when trying to figure out the circumference and diameter of a sex toy...especially a dildo. Size matters. At least correct size matters. If something is too big or too small disappointment is not far behind. For all of our products, we describe dimensions as accurately as we can. We even post warnings about ones that are really big and ask customers to take out a ruler and/or a measuring tape before placing an order. And it never fails, we still get calls and emails from dismayed customers saying that "…it was way bigger than I expected!" It is not an exact science and can be subjective. However, just so we are all close to being on the same page, here is how to measure a sex toy. It is the same for vibrators and dildos. If you still have trouble with the whole diameter and circumference thing, there are online calculators that can convert that for you. Remember...measure carefully, choose wisely, and stay sexy!
The length measurement indicates the entire length of the toy, from top to bottom including any handles and bases. With your toy placed on a flat surface, hold one end of the measuring tape at the tip of the toy's head and extend it to its base. Do not curl the measuring tape over the base.
The insertable length measurement indicates only the length of the toy that is meant for penetration. Hold one end of the measuring tape at the tip of the toy's head and extend it only to the end of the shaft. If your toy has a harness base, suction base, testicles, or a handle, it is not a part of the toy's insertable length measurement.
Width & Diameter
The width measurement indicates the horizontal diameter of the toy's surface at its widest point. Place one end of the measuring tape flat across its widest point. Do not curl the measuring tape around the edges of the toy.
Girth & Circumference
The girth measurement indicates the circumference of the toy around its widest point. With the toy held upwards, hold one end of the measuring tape at the center of its widest point, and wrap it around the toy until you're back where you started. Be sure not to overlap the measuring tape to get an accurate measurement.
PS. If you are still confused by measuring the width and circumference, there are online calculators that convert those measurements for you.