Not sure about your size?
No wonder, as it can vary dependant on which size chart you use. This is for my customers wanting to buy a ring but who isn't sure what size to ask for.
 
I have one, you have one and we know we have exactly the same measurement. This sizer is in UK format, but as long as we're talking about the same size it doesn't matter what chart it's following. :o)
 
The ring gauge works like a belt. Simply push the end through the buckle to form a ring shape. Slip the ring sizer on to your finger and adjust to give a comfortable fit, checking that it just slips back over the knuckle. Lightweight,reusable and easy to use. Comes with easy to follow instructions. (I don't make these - I buy them in and sell them at cost - no profit.)