Using our online ruler?
Calibrate first, then use MM mode to measure your ring diameter directly on screen.
📏 Method 1: The Paper Strip Method (Most Accurate)
What you need: A narrow strip of paper (about 0.5 cm wide, 10 cm long), a pen, and a ruler.
- Cut a narrow strip of paper and wrap it snugly, not tightly, around the base of the finger you want to size.
- With a pen, mark the exact point where the paper strip overlaps itself.
- Lay the strip flat on a table. Measure from the end to your pen mark in millimetres, this is your finger circumference.
- Divide your circumference by π (3.14159) to get your inner diameter in mm.
- Find your diameter in the ring size chart below.
Example: If your paper strip measures 58 mm, your inner diameter is 58 ÷ 3.14 = 18.5 mm ≈ US size 8½.
🧵 Method 2: Measure an Existing Ring
- Lay the ring flat on a ruler or on your screen with the online MM ruler.
- Measure the inner diameter: the distance across the inside of the ring.
- Look up that diameter in the table below.
📊 International Ring Size Chart
| US Size | UK Size | EU Size | Inner Diameter (mm) |
|---|---|---|---|
| 4 | H | 46.5 | 14.8 mm |
| 5 | J½ | 49 | 15.7 mm |
| 5.5 | K½ | 50 | 16.1 mm |
| 6 | L½ | 51.5 | 16.5 mm |
| 6.5 | M½ | 53 | 16.9 mm |
| 7 | N½ | 54 | 17.3 mm |
| 7.5 | O½ | 55.5 | 17.7 mm |
| 8 | P½ | 57 | 18.2 mm |
| 8.5 | Q½ | 58 | 18.6 mm |
| 9 | R½ | 59.5 | 19.0 mm |
| 10 | T½ | 62 | 19.8 mm |
| 11 | V½ | 65 | 20.6 mm |
💡 Tips for an Accurate Measurement
- Time of day: Measure in the afternoon or evening, fingers are at their largest then.
- Dominant hand: Your dominant hand is typically 0.5 a size larger.
- Wider bands: A wider band (over 6 mm) feels tighter. Consider going up half a size for wide rings.
- Between sizes: Always round up, a slightly loose ring is easier to resize than a tight one.
- Measure multiple times: Take 3 measurements and use the average.