The most reliable way to find someone's ring size without asking is to borrow a ring they already wear on the same finger and have it measured, or trace its inside edge and compare the diameter to a size chart. If you are unsure, choose the slightly larger size and a simple band, which is generally easier for a jeweler to adjust than a stone-set or patterned ring.
Last updated November 8, 2026 · Prices checked November 8, 2026
A ring is a personal gift, and the one most likely to go wrong for a practical reason: the fit. This guide covers how to work out a ring size quietly at home, which methods are worth trusting, what to do when you only have a rough idea, and which ring styles are more forgiving when you are not completely sure. If you want the full size chart and measuring steps for yourself, see our Ring Size Guide.
Start with the right finger
Before measuring anything, be clear about which finger the ring is for. Fingers on the same hand are different sizes, and the two hands differ too. GIA notes that for a right-handed person the left ring finger is typically about half a size smaller than the right, and vice versa. A ring borrowed from a middle finger or index finger will not tell you a ring-finger size.
If the gift is for the ring finger of the non-dominant hand, look for a ring they wear there regularly. If you can only find one they wear on the other hand, note that and adjust by roughly half a size down.
Four ways to find a ring size without asking
1. Borrow a ring and have it measured
This is the most accurate secret method. Take a ring they wear often on the right finger, preferably a plain band, and ask any local jeweler to check it on a ring mandrel (a tapered, size-marked rod). GIA recommends measuring wide bands from the center, since a wide ring sits differently from a slim one.
2. Trace or measure the inside of a ring at home
If you cannot take the ring out of the house, place it on a sheet of paper and trace the inside edge with a sharp pencil, or lay it on a ruler and measure the inside diameter in millimeters. Then compare it with a chart. As a quick reference for US and Canadian sizes:
- Size 5: about 15.7 mm inside diameter
- Size 6: about 16.5 mm
- Size 7: about 17.3 mm
- Size 8: about 18.1 mm
- Size 9: about 19.0 mm
Each half size is roughly 0.4 mm of diameter, so measure carefully and repeat it twice. Our Ring Size Guide has the full chart with circumference values.
3. Press a ring into a bar of soap
Another trick GIA describes: press the ring into a bar of soap to leave a clean impression, wipe the ring, return it, and bring the soap to a jeweler. It is less precise than measuring the ring itself, but it means the ring is gone for only a few seconds.
4. Ask someone who would know
A sibling, parent or close friend may already know the size, or can find out casually.
Methods to be careful with
Wrapping string or a strip of paper around a finger is often suggested online, but GIA cautions that string can stretch and paper can shift or curl, and that this method does not account for the knuckle, which is usually wider than the base of the finger. For a surprise gift it also needs the person's cooperation.
If you are between sizes
- Lean slightly larger. GIA points out that it is easier to remove metal from a ring that is too big than to add metal to one that is too small.
- Consider the band width. Wide bands fit more snugly, so they usually need to be a little larger. Our size guide suggests going up about half a size for bands of 6 mm or more.
- Think about the season. Fingers shrink in the cold and swell in the heat. A ring measured on a cold December morning can feel tighter by summer.
- Aim for snug, not tight. The ring should slide over the knuckle without force and not slip off when hands are washed.
Which ring styles are more forgiving
When the size is an educated guess, the design matters. GIA notes that pavé and channel settings, eternity bands with stones all the way around, twisted bands and multi-band designs are harder to resize. Plain or simply set bands are generally the easier choice. A few pieces that suit a gift when you are working from a careful estimate:
Simple bands in quarter sizes
The Perle Dorée Beaded Stackable Ring is a 2.5 mm beaded band offered in solid 14K yellow or white gold ($660.89) or 925 sterling silver ($90), in sizes 6 to 9 including quarter sizes. Quarter sizes help when your measurement lands between two whole sizes, and a narrow band is less sensitive to small differences.
The Élise 14K Gold Diamond Stackable Ring is a slim solid 14K band (about 1.7 mm wide) with nine round diamonds across the top, 1/8 CTW in total. It is $729.89 with lab-grown diamonds or $779.89 with natural diamonds, in sizes 6 to 8.5 including quarter sizes.
Pieces with a fixed set of sizes
The Éveline 14K Gold Freshwater Pearl Ring ($499.89) sets 3 mm cultured freshwater pearls along a 14K yellow gold band. It comes in whole sizes 5, 6, 7 and 8 only, so it works best when you are confident of the whole size. If your estimate falls on a half size, a quarter-size style above may be the safer pick.
The Valérie Gold Vermeil Diamond Criss Cross Ring ($399.89) is gold vermeil with 1/2 CTW of lab-grown diamonds, sizes 6 to 8.5. Under the FTC's Jewelry Guides, "vermeil" means a sterling silver base coated with gold of at least 10 karat and a minimum thickness of 2.5 microns, so it calls for gentler care than solid gold. See our guide to solid gold, gold-filled and vermeil for the differences.
Wide and personalized rings: be most certain
The Riviera 14K Gold Dome Ring ($2,199.89) comes in 8 mm or 12 mm widths, in 14K yellow or white gold, sizes 6 to 8.5. At these widths, follow the wide-band advice above and size up slightly.
The 14K Gold Engravable Signet Ring ($749) is solid 14K yellow gold with an engraving plate, sizes 5.5 to 9. Engraved pieces are personalized, and under our return policy personalized items cannot be returned unless defective. Only order this one when you have measured a ring rather than estimated.
You can browse more styles in our Rings collection.
If you really cannot find out
Sometimes there is no ring to borrow and no one to ask. In that case, consider a gift that does not depend on fit, such as a necklace, and plan the ring together later. Our guide to choosing a necklace length covers that route, and the Christmas gifts for her under $500 guide has more ideas.
How we chose these pieces
Every ring linked here states its metal on the product page, ships from the United States, was in stock when we checked, and is priced at $90 or more. Specifications and sizes come from the product listings, and the sizing advice draws on GIA guidance and our own size chart. Prices and availability can change, so check the product page before ordering.
FAQ
What is the most accurate way to find a ring size secretly?
Borrow a ring the person wears on the same finger and have a jeweler measure it on a ring mandrel. Tracing or measuring the inside diameter at home and comparing it to a size chart is the next best option.
Should I size up or down if I am not sure?
Size up slightly. It is generally easier to make a ring smaller than larger, and wide bands usually need about half a size more than slim ones.
Is the string method accurate?
Not very. String can stretch and paper can shift, and neither accounts for the knuckle. It also needs the person's cooperation, so it does not work for a surprise.
Which rings are hardest to resize?
Pavé and channel-set rings, full eternity bands, twisted bands and multi-band designs are harder to resize, so get the size right before choosing one of these styles.
