Ring Size Converter
Convert ring sizes between US, UK/AU, EU, JP, KR and circumference/diameter (mm) instantly
📏 How to Measure Your Ring Size
🧵 String / Thread Method
- Wrap a piece of string or thread snugly around the base of your finger.
- Mark where the string overlaps with a pen.
- Lay the string flat and measure the length in millimeters.
- This is your circumference — use the converter above to find your size.
📄 Paper Strip Method
- Cut a thin strip of paper (about 10mm wide, 100mm long).
- Wrap it around the base of your finger — snug but comfortable.
- Mark where the paper overlaps.
- Measure the length from the edge to the mark in millimeters.
- Enter this circumference in the converter above.
💍 Existing Ring Method
- Place a ring that fits well on a ruler.
- Measure the inside diameter in millimeters.
- Enter this diameter in the converter above.
🌡️ Seasonal & Sizing Tips
☀️ Fingers swell in warm weather. If you're between sizes, size up in summer.
❄️ Fingers shrink in cold weather. A ring that fits in winter may be loose in summer.
🕐 Measure in the evening when fingers are at their largest.
✋ Your dominant hand is typically slightly larger. Measure the specific finger you'll wear the ring on.