Ring Size Calculator
Convert ring sizes between US, UK, and EU systems, or find your size from finger measurements. Perfect for online jewelry shopping or surprise engagement rings.
Enter a ring size or measurement to see conversions.
How to Measure
Using string: Wrap a thin string or paper strip around your finger. Mark where it overlaps, then measure the length in mm. That's your circumference.
Using an existing ring: Measure the inside diameter of a ring that fits well on the intended finger. Make sure to measure across the center.
Frequently Asked Questions
Do ring sizes change?
Yes. Fingers swell in heat and shrink in cold. They're typically larger at the end of the day. Weight changes can also affect size. Measure when your hands are at normal temperature and not immediately after exercise.
How do I secretly find someone's ring size?
Borrow a ring they wear on that finger and trace the inside or press it into soap. Ask friends/family if they know. Compare their finger to yours while holding hands. Many jewelers offer free resizing within a certain timeframe.
What's the most common ring size?
For women, sizes 5-7 are most common (average around 6). For men, sizes 8-12 are typical (average around 10). However, individual variation is significant, so always measure when possible.