Determining the size of the ring using the filament
You will need: dense enough yarn (yarn is ideal to use for knitting napkins), preferably cotton, smooth. About 50 cm - to be comfortable to hold still.
The easiest way to find out what size ring you need at one time or another finger - is go to the nearest jewelry store and ask to measure your finger.
In any jewelry store have special patterns to determine the size of fingers.
If you do not have time to go into the jewelry, you can determine the size of a finger and, accordingly, the ring that will suit you, at home.
There are many ways how to do it. Here are some of the most interesting ones.
Steps for a goal
Take the thread, gently wrap the 5 turns down your finger (the width of "winding" of all 5 loops should be about 3-6 mm). No need to be wound tight, but still thread should be tightly pressed against the finger.
Wrap your finger, crossed both ends of the thread (without lifting your finger from) and at the same time cut the sharp shears them. Or simply mark the intersection of the ends of the thread with a pen or marker, unwind the thread and trim it on labels.
Measure ruler or tape measure centimeter length of yarn that you cut. The resulting length in inches, divide by 15.7. The resulting value is the size of the ring finger, which you measured. The resulting amount shall be rounded up to half a millimeter in a big way. For example, 17.1 to 17.5.