Omrekentabel ringmaten
GemRings! uses European (ISO) ring sizes. An EU ring size is simply the inside circumference of the ring in millimetres, so EU 52 means a 52 mm inner circumference. Use the chart below to convert between EU, US and UK ring sizes, or to find your size in millimetres from a ring that already fits. Our rings come in EU sizes 50, 52 and 54 (highlighted in the chart).
How to measure your ring size
Method 1: paper strip (finger circumference)
- Cut a thin strip of paper or use a piece of non-stretchy string.
- Wrap it snugly around the base of the finger you will wear the ring on. It should be close-fitting but not tight.
- Mark the point where the paper overlaps, then lay it flat and measure the length in millimetres.
- That number is your EU size. Find it in the circumference column below to see your US and UK size.
Check that the ring will still pass over your knuckle: if your knuckle is wider than the base of your finger, measure it too and pick a size between the two values.
Method 2: measure a ring that already fits
Place a ring that fits the same finger on a ruler and measure the inside diameter, from inner edge to inner edge, in millimetres. Find that value in the diameter column. A 16.6 mm inner diameter, for example, is EU 52, US 6, UK L½.
Ring size conversion chart (EU, US, UK)
If you are between sizes, choose the larger size for comfort.
| EU | Diameter (mm) | Circumference (mm) | US | UK |
|---|---|---|---|---|
| 46 | 14.6 | 46.0 | 3.75 | H |
| 47 | 15.0 | 47.0 | 4 | H½ |
| 48 | 15.3 | 48.0 | 4.5 | I½ |
| 49 | 15.6 | 49.0 | 5 | J½ |
| 50 | 15.9 | 50.0 | 5.25 | K |
| 51 | 16.2 | 51.0 | 5.75 | L |
| 52 | 16.6 | 52.0 | 6 | L½ |
| 53 | 16.9 | 53.0 | 6.5 | M½ |
| 54 | 17.2 | 54.0 | 6.75 | N½ |
| 55 | 17.5 | 55.0 | 7.25 | O |
| 56 | 17.8 | 56.0 | 7.75 | P |
| 57 | 18.1 | 57.0 | 8 | P½ |
| 58 | 18.5 | 58.0 | 8.5 | Q½ |
| 59 | 18.8 | 59.0 | 8.75 | R |
| 60 | 19.1 | 60.0 | 9.25 | S |
Sizes in bold are the sizes available at GemRings!. Conversions are rounded to the nearest quarter (US) or half letter (UK), so different charts can differ by a quarter size.
US to EU ring size
To convert a US ring size to a European size, find the US size in the chart and read the EU number on the same row. As a rule of thumb, each full US size adds about 2.5 mm of circumference. The most common women's sizes convert like this: US 5 = EU 49, US 6 = EU 52, US 6.75 = EU 54, US 7 is between EU 54 and 55, and US 8 = EU 57. In the other direction, a European ring size 50 is a US 5.25 and EU 54 is a US 6.75.
UK to EU ring size
UK and Australian ring sizes use letters, with half sizes in between. One full letter adds 1.25 mm of circumference. To convert UK to EU, find the letter in the chart: UK K = EU 50, UK L½ = EU 52, UK N½ = EU 54 and UK O = EU 55. To go from UK to US, read across the same row: a US size 6 is a UK L½.
Ring sizes in mm
Every ring size can be expressed in millimetres as an inner circumference or an inner diameter. EU sizes already are millimetres. For UK letter sizes, these are the standard values:
- UK J: 48.8 mm circumference, 15.5 mm diameter
- UK K: 50.0 mm circumference, 15.9 mm diameter
- UK L: 51.3 mm circumference, 16.3 mm diameter
- UK M: 52.5 mm circumference, 16.7 mm diameter
- UK N: 53.8 mm circumference, 17.1 mm diameter
- UK O: 55.0 mm circumference, 17.5 mm diameter
- UK P: 56.3 mm circumference, 17.9 mm diameter
- UK Q: 57.5 mm circumference, 18.3 mm diameter
US ring sizes in mm: US 5 is about 15.7 mm in diameter (49.3 mm around), US 6 is 16.5 mm (51.8 mm), US 7 is 17.3 mm (54.4 mm) and US 8 is 18.1 mm (56.9 mm).
Tips for the right fit
- Between two sizes? Choose the larger one. A slightly loose ring is more comfortable than a tight one.
- Wide bands: rings with a wide band sit tighter, so consider going up one size.
- Measure in the evening: fingers are slightly larger at the end of the day and smaller when cold, so avoid measuring right after being outside in the cold.
- Measure two or three times and use the value that comes up most often.
Ring size FAQ
Why are European, UK and US ring sizes different?
Each system follows its own standard. European sizes (ISO 8653) are the inner circumference in millimetres, US sizes use a numerical scale with quarter and half sizes, and UK sizes use letters from A to Z with half sizes. They are not interchangeable, so always use a conversion chart.
What is the most accurate way to find my ring size?
Measuring in millimetres. Whether you measure your finger's circumference or the inside diameter of a ring that fits, a millimetre value is the most reliable reference and converts directly to an EU size.
What is the average ring size?
Most women wear between EU 49 and 55 (US 5 to 7.25), with US 6 to 7 often quoted as the average. Men's sizes are usually larger, commonly around US 9 to 10 (EU 59 to 62).
What ring sizes does GemRings! offer?
Our rings are available in EU sizes 50, 52 and 54. Use the chart above to check which one matches your US or UK size.
Still unsure? Message us. Then browse all rings.