The most ideal and easy way to measure your ring size at home!
The ring sizer loops around like a belt, which you can then slide onto your finger (like you would a ring) and tighten to a snug fit. You want it to be loose enough so that it can slide on over your knuckle at the same size at where you are wanting the ring to sit.
You can then read the notch which the sizer sits at. The U.K. sizes read A - Z+9.
It should be noted that if you feel like you are in-between sizes, I can make half sizes too, so please just let me know when ordering your ring.