Inside diameter- First, select a ring that fits the finger. Next, measure the inside diameter of that ring. Use the chart below to determine your ring size.
Circumference- First, cut a narrow strip of paper and wrap it firmly around the finger. Make a mark where the two ends join. Next, unroll the paper and measure with a ruler the length between the two marks. Use the chart below to determine your ring size.
Equivalence- If you know your size in any scale ( UK, US, Euro) you can find its equivalent in the chart below