Ring Size Calculator
Find ring size from finger circumference or ring diameter. Includes approximate US, UK, and EU ring size conversion.
mm
mm
US Size 8
UK Size P
EU Size 57
Diameter 18.1 mm
Circumference 57.0 mm
Frequently Asked Questions
- You can measure the finger circumference with a strip of paper or a tape measure, then compare that value to a ring size chart. You can also measure the inner diameter of a ring that already fits.
- Both methods are used. Circumference is the distance around the finger, while diameter is the inside width across the ring. Either one can be converted into a ring size.
- Common adult ring sizes often fall around US 5 to 9 for women and US 8 to 12 for men, but there is a wide range and no single normal size.
- If your hands regularly swell because of heat or activity, a slightly larger size may feel better. Many jewelers suggest measuring later in the day, when fingers are closer to their larger size.
- It is a useful estimate, especially for online shopping, but exact fit can vary with ring width, comfort fit design, and how the jeweler sizes the band.
- Yes. Ring size charts often map a US number to a UK letter and an EU circumference size. This calculator gives an approximate conversion.
- Yes. Wider bands often feel tighter than narrow bands, so some people go up a quarter or half size for a wider ring.
- Yes. Many ring size tools use millimeters for finger circumference and ring diameter because the measurements are more precise.