How to measure your ring size at home
- Calibrate first. Open the ruler calibration and match the credit card outline. Without it, the circle won't be actual size.
- Use a ring that fits the right finger. Fingers differ, and your dominant hand is usually a little larger.
- Match the inside edge. Lay the ring flat on the circle and resize until the blue line sits just inside the metal, not on its outer edge.
- Read your size. If you're between sizes, choose the larger one, especially for wide bands.
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) | J½ |
| 6 | 16.5 mm | 51.9 mm (52) | L½ |
| 7 | 17.3 mm | 54.4 mm (54) | N½ |
| 8 | 18.1 mm | 57 mm (57) | P½ |
| 9 | 18.9 mm | 59.5 mm (60) | R½ |
| 10 | 19.8 mm | 62.1 mm (62) | T½ |
| 11 | 20.6 mm | 64.6 mm (65) | V½ |
| 12 | 21.4 mm | 67.2 mm (67) | Y |
| 13 | 22.2 mm | 69.7 mm (70) | Z+1 |
Each full US size adds about 0.81 mm to the inside diameter (2.55 mm of circumference). Fingers swell when warm and shrink when cold, so measure at room temperature, ideally in the evening.
How do I find my ring size online?
Calibrate your screen once, place a ring that fits on the circle, and adjust the circle until its edge sits on the inside edge of the ring. The tool shows the inside diameter and your US, UK and EU ring size.
Is an online ring sizer accurate?
After calibration it is typically accurate to within about a quarter size. Each US size is only about 0.8 mm of diameter, so take your time, look straight down, and confirm with a jeweler before buying an expensive ring.
What is the EU ring size?
The EU (ISO 8653) size is the inside circumference of the ring in millimeters. A ring with a 54.4 mm inside circumference is EU size 54, about a US 7.