Ring education · Sizing
A ring that fits is as important as the diamond in it. Use the US ring size chart below to convert finger measurements to a ring size, and follow the at-home methods to measure yourself or discreetly find a partner's size.
| US size | Diameter (mm) | Circumference (mm) |
|---|---|---|
| 3 | 14.1 | 44.2 |
| 3.5 | 14.5 | 45.5 |
| 4 | 14.9 | 46.8 |
| 4.5 | 15.3 | 48.0 |
| 5 | 15.7 | 49.3 |
| 5.5 | 16.1 | 50.6 |
| 6 | 16.5 | 51.9 |
| 6.5 | 16.9 | 53.1 |
| 7 | 17.3 | 54.4 |
| 7.5 | 17.7 | 55.7 |
| 8 | 18.1 | 57.0 |
| 8.5 | 18.5 | 58.2 |
| 9 | 18.9 | 59.5 |
| 9.5 | 19.4 | 60.8 |
| 10 | 19.8 | 62.1 |
| 10.5 | 20.2 | 63.3 |
| 11 | 20.6 | 64.6 |
| 11.5 | 21.0 | 65.9 |
| 12 | 21.4 | 67.2 |
| 12.5 | 21.8 | 68.5 |
| 13 | 22.2 | 69.7 |
Cut a thin strip of paper, wrap it snugly around the base of the finger, and mark the overlap. Lay it flat against a millimetre ruler and read the circumference, then find the nearest size in the chart. Repeat two or three times for consistency.
Place a ring that already fits on a ruler and measure the inside diameter edge to edge in millimetres. Match that number to the diameter column. Use a ring worn on the same finger and hand, since dominant-hand fingers are often slightly larger.
Fingers swell with heat, exercise and salt, and shrink in the cold. Measure at room temperature at the end of the day for the most reliable reading, and avoid measuring right after a workout.
Band width and profile change fit. Wide or flat-profile bands feel tighter; comfort-fit bands feel looser. The True Carat wedding band calculator uses your ring size to calculate circumference and metal weight, so the price reflects the size you choose.
Wrap a thin strip of paper or string around the base of your finger, mark where it overlaps, and measure the length in millimetres. That is your circumference — match it to the chart. Measure at the end of the day when fingers are largest, and make sure it slides over the knuckle.
In the US the most common women's ring sizes are around 6 to 7, and men's around 9 to 10. Averages are only a starting point; always measure.
Borrow a ring they wear on the same finger and measure its inside diameter against the chart, or trace the inside of it on paper. You can also ask a friend or family member. If unsure, size up slightly — rings are easier to size down than up.
Yes. Wide bands of about 6 mm or more fit more snugly, so many people go up a quarter to half size for wide wedding bands or comfort-fit profiles feel slightly looser.
Most gold and platinum rings can be resized one or two sizes. Eternity bands, channel-set and full pavé rings are difficult or impossible to resize, so get the size right before ordering those styles.