How to measure your ring size at home
- Cut a thin strip of paper, about 5 mm wide and 10 cm long.
- Wrap it around the base of the finger, snug but not tight. It should slide over the knuckle.
- Mark the point where the paper overlaps.
- Lay the strip flat and measure the length in millimetres. This is your circumference.
- Find the closest circumference in the chart below.
How to calculate your ring size
You only need one measurement to work out every international size:
- EU and German size = inner circumference in millimetres. A circumference of 54 mm is EU size 54.
- Diameter = circumference ÷ 3.14. A circumference of 54 mm equals a diameter of about 17.2 mm.
- US size ≈ (diameter in mm − 11.63) ÷ 0.8128. A diameter of 17.2 mm is about US size 7.
In Germany, ring sizes are usually given as the circumference (for example 54), but some jewellers also use the inner diameter (for example 17.2). Our chart shows both.
International ring size conversion chart
| EU / DE | US / CA | UK / AU | Diameter (mm) | Circumference (mm) |
|---|---|---|---|---|
| 44 | 3.0 | F | 14.1 | 44.2 |
| 45 | 3.5 | G½ | 14.5 | 45.5 |
| 47 | 4.0 | H½ | 14.9 | 46.8 |
| 48 | 4.5 | I½ | 15.3 | 48.0 |
| 49 | 5.0 | J½ | 15.7 | 49.3 |
| 51 | 5.5 | K½ | 16.1 | 50.6 |
| 52 | 6.0 | L½ | 16.5 | 51.9 |
| 53 | 6.5 | M½ | 16.9 | 53.1 |
| 54 | 7.0 | N½ | 17.3 | 54.4 |
| 56 | 7.5 | O½ | 17.7 | 55.7 |
| 57 | 8.0 | P½ | 18.1 | 57.0 |
| 58 | 8.5 | Q½ | 18.5 | 58.2 |
| 60 | 9.0 | R½ | 18.9 | 59.5 |
| 61 | 9.5 | S½ | 19.4 | 60.8 |
| 62 | 10.0 | T½ | 19.8 | 62.1 |
| 63 | 10.5 | U½ | 20.2 | 63.3 |
| 65 | 11.0 | V½ | 20.6 | 64.6 |
| 66 | 11.5 | W½ | 21.0 | 65.9 |
| 67 | 12.0 | X½ | 21.4 | 67.2 |
| 68 | 12.5 | Z | 21.8 | 68.5 |
| 70 | 13.0 | Z+1 | 22.2 | 69.7 |
Conversions are rounded; when a measurement falls between two sizes, choose the larger one.
Tips for a perfect fit
- Measure at the end of the day. Fingers are smallest in the morning and in cold weather, and largest in the evening and in warm weather.
- Measure three times. Take the average of measurements on different days.
- Mind the knuckle. If the knuckle is wider than the base of the finger, choose a size that slides over it comfortably.
- Wide bands fit tighter. For bands wider than 4 mm, go up half to one size.
- The dominant hand is larger. The right ring finger is often half a size bigger than the left.
Keeping the proposal a surprise
Borrow a ring she wears on her ring finger and measure its inside diameter, or trace its inside on paper. Ask a friend or family member for help. And do not worry: every BEUSÉA ring includes one free resizing, so you can propose with confidence.
