Shopping for an engagement ring, wedding band, or surprise gift online? You don't need to visit a jeweler to get your sizing right. Using a simple strip of paper and our millimeter screen ruler, you can determine your exact size in under three minutes.
Method 1: The Paper Strip Finger Circumference Test
- Cut a narrow strip of paper about 1/2 inch (1 cm) wide and 4 inches long.
- Wrap the strip around the base of the finger you plan to wear the ring on. Make sure it feels snug but comfortable.
- Pull the paper over your knuckle to confirm it slides off comfortably.
- Use a pen to draw a clear line where the paper overlaps.
- Lay the paper flat on your screen against our MM Screen Ruler and read the exact millimeter length.
Method 2: Measuring an Existing Ring Inside Diameter
If you already own a ring that fits the desired finger perfectly:
- Place the ring flat on your phone or tablet screen on our Movable Real Scale Ruler.
- Measure the inside diameter across the widest inner edge in millimeters (do NOT include the ring's metal thickness).
International Ring Size Chart (US, UK, EU, MM)
| US Size | Inside Diameter (mm) | Inside Circumference (mm) | UK Size | EU / ISO Size |
|---|---|---|---|---|
| 4 | 14.9 mm | 46.8 mm | H 1/2 | 47 |
| 5 | 15.7 mm | 49.3 mm | J 1/2 | 49 |
| 6 | 16.5 mm | 51.9 mm | L 1/2 | 52 |
| 7 | 17.3 mm | 54.4 mm | N 1/2 | 54 |
| 8 | 18.1 mm | 57.0 mm | P 1/2 | 57 |
| 9 | 19.0 mm | 59.5 mm | R 1/2 | 60 |
| 10 | 19.8 mm | 62.1 mm | T 1/2 | 62 |
| 11 | 20.6 mm | 64.6 mm | V 1/2 | 65 |
| 12 | 21.4 mm | 67.2 mm | X 1/2 | 67 |
