Why the right size matters
A ring that is too loose spins, slips off in cold water and puts the center stone at risk. A ring that is too tight is uncomfortable and gets left in a drawer. Getting close the first time also matters for the setting you choose, because some rings are easy to resize and some are not.
The good news: you do not need to be exact to the quarter size before you visit. You need a sensible starting point. We check the final size on the hand in the showroom whenever that is possible.
US ring size chart
Ring sizes in the United States run on a number scale. Each whole size adds about 0.8 mm to the inside diameter. Use the table to match a ring that already fits, or a measurement you have taken.
| US size | Inside diameter (mm) | Inside 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 | 58.3 |
| 9 | 18.9 | 59.5 |
| 9.5 | 19.4 | 60.8 |
| 10 | 19.8 | 62.1 |
| 10.5 | 20.2 | 63.4 |
| 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 |
Three ways to measure at home
Measure a ring that already fits
This is the most reliable home method. Take a ring that fits the right finger well. Lay it flat on a ruler and measure the inside edge to inside edge, across the widest point, in millimeters. Match that number to the inside diameter column. If you can, bring the ring with you to the viewing instead and we will read it on a sizing mandrel.
Measure the finger with string or paper
Wrap a thin strip of paper or a piece of non stretch string around the base of the finger. Mark where it meets, then measure the length flat against a ruler. That is the circumference. This method is easy but rough. String stretches and paper can be pulled too tight, so treat the result as a range, not a final answer.
Use a plastic ring sizer
Adjustable plastic sizers are cheap and better than string. Fit it so it slides over the knuckle with a little resistance and does not spin freely at the base.
Finding a size when the ring is a surprise
Many people buying an engagement ring cannot simply ask. Some quiet ways to find a size:
- Borrow a ring they wear on the ring finger, for an hour, and bring it to us or measure it as above. Make sure it is from the correct hand and finger.
- Press a ring into soap or clay to get a clean outline of the inside if you cannot take it out of the house.
- Trace the inside of a ring on paper, both the inner and outer edge, and bring the tracing.
- Ask a close friend or family member who may already know, or who can find out without giving the plan away.
- Size up if unsure. A ring that is slightly large is easier to adjust than one that will not go on at all.
Things that change the fit
Band width
Wide bands feel tighter than narrow bands of the same size because they cover more of the finger. For bands about 6 mm or wider, many people go up a quarter or half size. This matters most for men's bands and wide wedding bands.
Temperature and time of day
Fingers swell in heat, after exercise and later in the day, and shrink in the cold. Measure at a normal room temperature and not first thing in the morning or right after a workout.
Knuckles
If your knuckle is much larger than the base of your finger, the ring has to pass the knuckle and then may feel loose at the base. Small sizing beads inside the band can help. Ask us about them at your visit.
Stacking
An engagement ring and a band worn together can feel snug. If you plan to wear both, try them on together before settling the size.
Resizing: which rings can and cannot change
Most plain gold and platinum bands can be sized up or down by a size or two. The design of the ring is what limits it.
- Solitaires and simple bands are usually easy to adjust.
- Pave and half eternity bands can be adjusted a little, but stones near the bottom of the shank limit how far.
- Full eternity bands, with diamonds all the way around, generally cannot be resized. Get the size right before it is made.
- Tension and some custom settings may need to be remade rather than resized.
If resizing might matter later, tell us when you choose a setting. Policies and costs for sizing are arranged at your visit, so ask us about them directly. Our solitaire settings are the most flexible if you are unsure of the size.
Get sized at the showroom
The easiest option is to come in. We measure with metal sizing rings that match the width of the band you are considering, which is more accurate than string or plastic. If the ring is a surprise, bring a borrowed ring or a tracing and we will work from that. Book a viewing at 30 West 47th St, Suite 805, and look through engagement ring settings or request loose stones to see on the same visit. You can also call us on (732) 581-7932.
