Find your perfect ring size at home
Wrap paper/string around finger and measure the length
🇺🇸 US
7
🇬🇧 UK
N
🇪🇺 EU
54
🇯🇵 JP
14
Diameter
17.3 mm
Circumference
54.4 mm
| US | UK | EU | JP | ∅ mm |
|---|---|---|---|---|
| 4.5 | I | 48 | 8 | 15.3 |
| 5 | J | 49 | 9 | 15.7 |
| 5.5 | K | 50 | 10 | 16.1 |
| 6 | L | 51 | 11 | 16.5 |
| 6.5 | M | 53 | 13 | 16.9 |
| 7 | N | 54 | 14 | 17.3 |
| 7.5 | O | 55 | 15 | 17.7 |
| 8 | P | 57 | 16 | 18.1 |
| 8.5 | Q | 58 | 17 | 18.5 |
| 9 | R | 59 | 18 | 18.9 |
| 9.5 | S | 60 | 19 | 19.4 |
| 10 | T | 62 | 20 | 19.8 |
Tip: Measure at the end of the day when fingers are slightly larger. If between sizes, choose the larger size for comfort.
Inputs
Result
A circumference of 54 mm is closest to the size chart entry at 54.4 mm, which corresponds to US 7, UK N, EU 54, JP 14, with an inner diameter of 17.3 mm.
Inputs
Result
A diameter of 19.8 mm matches exactly to the chart entry for US 10, UK T, EU 62, JP 20, with a circumference of 62.1 mm.
Method 1 (string): Wrap string around finger, mark overlap, measure in mm. This is circumference. Method 2 (existing ring): Measure inner diameter in mm. Method 3 (printable sizer): Use online ring sizer at actual size.
| Circumference (mm) | Diameter (mm) | US Size | UK Size |
|---|---|---|---|
| 49.3 | 15.7 | 5 | J½ |
| 51.9 | 16.5 | 6 | L½ |
| 54.4 | 17.3 | 7 | N½ |
| 57.0 | 18.1 | 8 | P½ |
| 59.5 | 19.0 | 9 | R½ |
| 62.1 | 19.8 | 10 | T½ |
Women's average: US 6-7 (16.5-17.3mm diameter). Men's average: US 9-10 (19-20mm diameter). Engagement rings for women: Most commonly size 5-7. Wedding bands for men: 8-12. Always measure - averages vary widely.
| Category | US Size Range | Most Common | Diameter (mm) |
|---|---|---|---|
| Women's engagement | 4-8 | 6 | 16.5mm |
| Women's wedding band | 5-7 | 6-6.5 | 16.5-16.9mm |
| Men's wedding band | 8-12 | 10 | 19.8mm |
| Pinky ring | 4-7 | 5 | 15.7mm |
| Thumb ring | 7-13 | 9-10 | 19-20mm |
EU sizes = circumference in mm. US sizes are numbered 1-16 with half sizes. UK uses letters A-Z. Example: US 7 = UK N½ = EU 54. Use our converter for exact translations between any sizing system.
| US Size | UK Size | EU Size | Diameter (mm) |
|---|---|---|---|
| 5 | J½ | 49 | 15.7 |
| 6 | L½ | 52 | 16.5 |
| 7 | N½ | 54 | 17.3 |
| 8 | P½ | 57 | 18.1 |
| 9 | R½ | 59 | 19.0 |
| 10 | T½ | 62 | 19.8 |
| 11 | V½ | 65 | 20.6 |
| 12 | Y | 67 | 21.4 |
Measure at end of day (fingers slightly swollen), at room temperature, when relaxed. Avoid: Cold weather (fingers shrink), after exercise (swollen), morning (often smaller), salty food (water retention).
Wider bands need larger sizes. A wide band (6mm+) fits tighter than a thin band (2-3mm). Go up ½ size for 6-8mm bands, full size up for 8mm+ bands. Try on similar width rings if possible.
| Band Width | Size Adjustment | Common Use |
|---|---|---|
| 2-3mm (thin) | True to size | Women's bands, stackable |
| 4-5mm (medium) | True to size | Classic wedding bands |
| 6-7mm (wide) | +½ size | Men's bands |
| 8mm+ (extra wide) | +½ to +1 size | Statement rings |
Most rings can be resized 1-2 sizes up or down. Cost: $30-100 at jeweler. Some rings cannot be resized: Eternity bands (stones all around), tungsten/titanium, certain engraved or intricate designs.
| Ring Type | Can Resize? | Notes |
|---|---|---|
| Plain gold/silver | Yes, easily | Up to 2 sizes |
| Solitaire diamond | Yes | May need prong adjustment |
| Eternity band | No | Stones all around |
| Tungsten carbide | No | Cannot be cut |
| Titanium | No | Very difficult |
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Last Updated: Feb 12, 2026
This calculator is provided for informational and educational purposes only. Results are estimates and should not be considered professional financial, medical, legal, or other advice. Always consult a qualified professional before making important decisions. UseCalcPro is not responsible for any actions taken based on calculator results.