How to Measure Your Ring Size: Chart and Guide
Want to buy or give a ring but don't know the size? With a piece of string and our ring size chart, you can find it in 2 minutes. You will also learn what sizes like "ring size 17" mean and how to convert EU, CH and US sizes.
Ring Size Chart: EU, CH, US and Diameter
In Switzerland and the EU, ring size is the inside circumference of the ring in millimeters. Size 54 means a circumference of 54 mm. The diameter is the distance straight across the inside of the ring. The sizes available at Cosytas are shown in bold.
| Size EU/CH | Circumference | Diameter | US (approx.) |
|---|---|---|---|
| 48 | 48 mm | 15.3 mm | 4.5 |
| 49 | 49 mm | 15.6 mm | 5 |
| 50 | 50 mm | 15.9 mm | 5 |
| 51 | 51 mm | 16.2 mm | 5.5 |
| 52 | 52 mm | 16.6 mm | 6 |
| 53 | 53 mm | 16.9 mm | 6.5 |
| 54 | 54 mm | 17.2 mm | 7 |
| 55 | 55 mm | 17.5 mm | 7.5 |
| 56 | 56 mm | 17.8 mm | 7.5 |
| 57 | 57 mm | 18.1 mm | 8 |
| 58 | 58 mm | 18.5 mm | 8.5 |
| 59 | 59 mm | 18.8 mm | 9 |
| 60 | 60 mm | 19.1 mm | 9 |
| 61 | 61 mm | 19.4 mm | 9.5 |
| 62 | 62 mm | 19.7 mm | 10 |
How to Measure Your Ring Size
With a Piece of String or Paper
- Wrap a piece of string or a thin strip of paper around the finger you want to wear the ring on. Do not pull too tight.
- Mark the spot where the ends meet with a pen.
- Lay the string flat and measure the length in millimeters with a ruler.
- This number is your ring size (EU/CH). Example: 54 mm equals size 54.
Important: The ring also has to fit over your knuckle. Check that the loop slides comfortably over it.
With a Ring That Fits You Well
- Place the ring on a ruler.
- Measure the diameter from inner edge to inner edge in millimeters.
- Find the value in the diameter column. Your size is right next to it.
At a Jeweler
The most accurate way is a ring sizer at a jeweler. It only takes a minute.
Ring Size 17, 18 or 19: What Does It Mean?
In Germany and with some brands, ring size is given as the inside diameter in mm. "Ring size 17" then means a diameter of 17 mm. That is roughly size 53 in Switzerland and the EU. To convert it yourself: diameter × 3.14 = circumference = size EU/CH.
| Diameter | Size EU/CH | US (approx.) |
|---|---|---|
| 15.5 mm | 49 | 5 |
| 16 mm | 50 | 5 |
| 16.5 mm | 52 | 6 |
| 17 mm | 53 | 6.5 |
| 17.5 mm | 55 | 7.5 |
| 18 mm | 57 | 8 |
| 18.5 mm | 58 | 8.5 |
| 19 mm | 60 | 9 |
| 19.5 mm | 61 | 9.5 |
Tips for the Perfect Fit
- Measure in the evening and at a normal temperature. In the morning and in the cold, fingers are slightly slimmer; in the heat, slightly thicker.
- Measure on the hand you want to wear the ring on. The fingers of your writing hand are often a little larger.
- For wide rings (from about 6 mm wide), choose one size larger, as they sit tighter.
- If you are between two sizes, choose the larger one.
- Want to give a ring as a gift? Discreetly borrow one of the person's rings and measure the inside diameter.
What Ring Size Do Most Women Wear?
Many women wear a size between 52 and 56 on their ring finger, most often 52 to 54 (US 6 to 7). This is only a guide, though. Fingers vary a lot, so it is worth taking a quick measurement yourself.
Ring Sizes at Cosytas
Our rings with size selection come in sizes 50, 52, 54 and 57 (EU/CH). That equals US 5, 6, 7 and 8. These sizes are shown in bold in the chart above. You choose your size directly on the product page.
Rings without size selection, such as Wave, Dune, Amore or Lava, have an open design. You can gently bend them a little tighter or wider so they adapt to your finger. Just do not bend them back and forth too often, so the metal stays beautiful.
Discover all Cosytas rings.
Frequently Asked Questions About Ring Size
How can I find my ring size without a tape measure?
With a piece of string or paper and a ruler. Wrap it around your finger, mark where the ends meet and measure the length in mm. This number is your size EU/CH.
What does ring size 17 mean?
It usually means an inside diameter of 17 mm. That is roughly size 53 (EU/CH) or US 6.5.
What is the smallest ring size?
In most charts, adult ring sizes start at around 44, which is a diameter of 14 mm. Even smaller sizes are mainly made for children. At Cosytas, the smallest fixed size is 50.
Are Swiss and EU ring sizes the same?
Yes. In Switzerland and many European countries, ring size is the circumference in mm. You only need to convert if the size is given as a diameter (for example 17) or as a US size.
What if my ring does not fit?
You can return it within 14 days, unworn and in its original packaging. An exchange is possible by agreement, provided the requested item is available. Sale items are excluded. You will find all details under Returns & Exchanges.