Ring Size Converter
Convert ring sizes between US, UK, EU (European), and Japanese systems. Use the diameter or circumference measurements for the most accurate cross-reference.
Ring Size Chart
Measure the internal diameter or internal circumference of a well-fitting ring, or measure your finger with a soft measuring tape.
| US | UK | EU / ISO | JP | Diameter (mm) | Circumference (mm) |
|---|---|---|---|---|---|
| 3 | F | 44 | 4 | 14.1 | 44.2 |
| 3.5 | G | 45 | 5 | 14.5 | 45.5 |
| 4 | H | 46.5 | 6 | 14.9 | 46.8 |
| 4.5 | I | 47.5 | 7 | 15.3 | 48.0 |
| 5 | J | 49 | 8 | 15.7 | 49.3 |
| 5.5 | K | 50.5 | 9 | 16.1 | 50.6 |
| 6 | L | 51.5 | 10 | 16.5 | 51.9 |
| 6.5 | M | 53 | 11 | 16.9 | 53.1 |
| 7 | N | 54 | 12 | 17.3 | 54.4 |
| 7.5 | O | 55.5 | 13 | 17.7 | 55.7 |
| 8 | P | 57 | 14 | 18.1 | 57.0 |
| 8.5 | Q | 58 | 15 | 18.5 | 58.3 |
| 9 | R | 59 | 16 | 18.9 | 59.5 |
| 9.5 | S | 60.5 | 17 | 19.4 | 60.8 |
| 10 | T | 61.5 | 18 | 19.8 | 62.1 |
| 10.5 | U | 62.5 | 19 | 20.2 | 63.4 |
| 11 | V | 64 | 20 | 20.6 | 64.6 |
| 11.5 | W | 65.5 | 21 | 21.0 | 65.9 |
| 12 | X | 66.5 | 22 | 21.4 | 67.2 |
| 12.5 | Y | 68 | 23 | 21.8 | 68.5 |
| 13 | Z | 69.5 | 24 | 22.2 | 69.7 |
How to Measure Your Ring Size
Method 1: Measure an existing ring
- Take a ring that fits the intended finger.
- Measure its internal diameter (across the inside) in millimeters.
- Match the measurement to the diameter column in the chart above.
Method 2: Measure the finger
- Wrap a strip of paper or a soft measuring tape around the base of the finger.
- Mark where the strip meets itself.
- Measure the length in millimeters — this is the circumference.
- Match the measurement to the circumference column in the chart.
Method 3: Use a ring sizer
Professional ring sizers are the most accurate. Jewelry stores offer this service for free, and reusable sizing tools can be purchased online.
Practical Tips
- Measure at the end of the day when fingers are largest.
- Avoid measuring after exercise or in cold weather — fingers can be smaller.
- If between sizes, choose the larger size for wide bands; choose the smaller size for thin bands.
- The dominant hand's ring finger is often half a size larger than the other hand's.
- Wider bands (5 mm and up) fit more tightly and may require a half-size up.
Related Converters
Frequently Asked Questions
What is a US size 7 ring in UK and EU?
US 7 ≈ UK N ≈ EU 54. The diameter is about 17.3 mm and circumference 54.4 mm.
How do I find my ring size at home?
Measure an existing ring's internal diameter in millimeters, or wrap a strip of paper around your finger, mark it, and measure the length in millimeters. Match the value against the chart above.
Are ring sizes the same for men and women?
Yes. The ring sizing systems are the same for both genders. Men typically have larger ring sizes because their fingers are generally larger.
What is the most common ring size?
In the US, the most common women's ring size is 6 to 7; the most common men's size is 9 to 10.
Can I resize a ring?
Most metal rings can be resized, but the range is limited (usually 2 sizes up or down). Rings with stones or intricate designs may be harder or impossible to resize. Consult a jeweler.