Ring size converter
Turn the inside diameter or circumference of a ring into a US ring size, then have a jeweler confirm it.
Closest sizeUS 7
17.3 mm inside diameter, 54.4 mm around. Have a jeweler confirm before you order.
Ring size chart
| US | Diameter | Circumference | EU | UK |
|---|---|---|---|---|
| 3 | 14.1 mm | 44.2 mm | 44 | F |
| 4 | 14.9 mm | 46.8 mm | 47 | H |
| 5 | 15.7 mm | 49.3 mm | 49 | J |
| 6 | 16.5 mm | 51.9 mm | 52 | L |
| 7 | 17.3 mm | 54.4 mm | 54 | N |
| 8 | 18.1 mm | 57.0 mm | 57 | P |
| 9 | 18.9 mm | 59.5 mm | 60 | R |
| 10 | 19.8 mm | 62.1 mm | 62 | T |
| 11 | 20.6 mm | 64.6 mm | 65 | V |
| 12 | 21.4 mm | 67.2 mm | 67 | X |
| 13 | 22.2 mm | 69.7 mm | 70 | Z |
Trying to find the size without asking? Read how to find a ring size quietly.
Questions readers ask
How do I measure a ring I already have?
Measure the inside of the ring straight across, in millimetres, from edge to edge. That is the inside diameter. Measure a ring that is worn on the same finger.
How accurate is a home measurement?
It gets you close, but a jeweler’s sizer is more reliable. Wide bands fit tighter, and fingers change size with temperature and time of day.
What if the ring is the wrong size?
Many rings can be resized by a jeweler, usually by a size or two, but some designs, such as eternity bands, are hard to resize. Ask before you buy.
Which finger should I measure?
The left ring finger for most engagement rings in the US. Dominant-hand fingers often run a little larger.
Are US, UK and EU sizes the same?
No. The table below lists the equivalents. EU sizes are based on the circumference in millimetres.