There are a few ways to figure out your ring size at home. The most accurate way is to visit a jewelry store and have a professional measure your finger.
If you can't make it to a jewelry store, you can use a string or a strip of paper to measure your finger. First, make a mark on the string or paper where it wraps around your finger. Then, use a ruler to measure the length from the mark to the end of the string or paper. Once you have your measurement, refer to a ring size chart to find your corresponding ring size.
Another way to measure your finger is to use a ring that already fits you. Place the ring over the circle on the ring size chart. The inside edge of the ring should line up with the ring size line. If it lines up with the line above the ring size, your ring is too small. If it lines up with the line below the ring size, your ring is too large.
If you're still unsure of your ring size, you can always ask a friend or family member to measure your finger for you.