How to Measure Your Ring Size at Home

You need a strip of paper about 6 mm wide, or a piece of string that does not stretch, plus a pen and a ruler marked in millimeters. Floss stretches. Yarn stretches. Skip both.

1. Cut a strip longer than the finger.
2. Wrap it at the base, not over the knuckle. Snug, not tight. You should be able to slide a fingernail under it.
3. Mark the overlap with a pen, on the paper, not by pinching string and hoping.
4. Lay it flat and measure from the end to the mark in millimeters.
5. Repeat twice more. If the three numbers disagree by more than 1 mm, the wrap was inconsistent. Average only the close ones.
6. Convert with the chart: circumference in mm equals 2.55 times the US size, plus 36.5. A measurement of 51.8 mm is a US 6. A measurement of 54.4 mm is a US 7.

The full table is the ring size chart. Write the millimeter down even after you pick a US size. That millimeter is what you read back to a jeweler.

A ring that already fits is a better tool than string. You are measuring metal, not a soft wrap.

• Diameter: set the ring on a ruler and measure the inside edge to the inside edge, across the center. Do not include the metal. A US 6 is about 16.5 mm across. A US 7 is about 17.3 mm across. Eyeballing this on a soft tape is worse than it sounds. Use a millimeter ruler and look straight down so you are not reading the near edge and the far edge at an angle.
• Circumference: if you have a narrow strip, wrap it around the outside and do not do that. Outside circumference includes the wall of the ring and will size you up. Inside only.
• Mandrel: jewelers slide the ring onto a tapered stick until it stops, then read the engraved size. That is the accurate version of this test. The showroom has that stick.

Match the finger. A ring from the index finger is not the ring finger. A pinky ring is not a clue. Right and left ring fingers often differ by a quarter size.

Getting the ring on is half the fit. Keeping it on is the other half. If your knuckle is wider than the base of the finger, a ring sized only to the base will not pass the joint, and a ring sized to the joint will spin once it is on.

The practical test: the ring should cross the knuckle with a little resistance, not with pain and not with soap as a requirement, and it should not spin freely at the base. If those two conditions cannot both be true, you need a fitter, not a tighter guess. Benches sometimes add small sizing beads inside a band so a ring cleared for a large knuckle still stays put. That is a known method, described in ring-making references. It is not a service listed in Franky's published policies. Ask before you assume it.

What can be changed later depends on the design. A plain band is the easy case in the trade. A band with stones set all the way around is often not resizable without rebuilding it. Read ring resizing before you order a size you hope to fix. The policies on the site do not list resizing.

Fingers are smaller in the morning and in the cold. They are larger at night, after a salty meal, during a flight, and in Miami heat. Measure at the end of the day, in the conditions you actually live in. If you are between sizes, take the larger one for a ring you will wear in this climate, unless the knuckle is the problem and the larger size will spin.

Do not measure after a workout or after a long walk in August if you can avoid the extreme. That reading is your maximum, and a ring sized only to your maximum may fall off in an office. The end of a normal day is the compromise. Measure the finger three times across a week if the order is an engagement ring. One Tuesday is not a finger.

Pregnancy, injury and a big weight change can move a size or more. If that is the season you are in, say so when you order. A ring that fits in month four may not fit in month eight, and that is not a defect in the ring.

Printable sizers fail when the printer scales to fit. Before you trust a printed ring, measure the printed scale bar with a ruler. If it is not exact, the whole sheet is junk. A plastic strip sizer from a jeweler is better. A set of metal rings is best, because you feel the knuckle.

String is fine for getting within about a half size when you are careful and the string does not stretch. It is a bad tool for a wide band, because the string is thin and the band is not. Review wide-band fit on the size chart page. Then look at the actual shanks on lab diamond engagement rings, including pear, radiant and emerald shapes. The stone shape does not change the measurement. The band width does.

The accurate close is in person. Bring a ring that fits, or just bring the hand. The showroom is at 7900 NW 27th Ave, Unit 506, Miami FL 33147. Phone 954-504-5640. Browse the ring case at rings after you have a number, not before.