How to Measure Your Ring Size Accurately
A well-fitting ring is comfortable, secure, and showcases the design perfectly. Whether you're buying for yourself or surprising a partner, accurate ring sizing is essential. This guide covers the most reliable methods, tips for accuracy, and what to do if the size is wrong.
Method 1: Measure an Existing Ring (Most Accurate)
If the person already has a well-fitting ring, this is the gold standard:
1. Take a ring that fits the intended finger (not the thumb — fingers vary in size).
2. Measure the INSIDE diameter with a ruler or digital calipers (measure in millimeters for precision).
3. Convert to ring size: 14.0mm = US 3, 14.9mm = US 4, 15.7mm = US 5, 16.5mm = US 6, 17.3mm = US 7, 18.1mm = US 8, 18.9mm = US 9, 19.8mm = US 10.
4. For wide bands (6mm+), measure a wide ring if possible — wide bands fit tighter and may require going up 1/4-1/2 size.
Method 2: Measure the Finger
If no existing ring is available:
1. Use a strip of paper or non-stretchy string.
2. Wrap snugly around the base of the intended finger, mark where it overlaps.
3. Measure the length in millimeters (circumference).
4. Convert: 44.2mm = US 3, 46.8mm = US 4, 49.3mm = US 5, 51.8mm = US 6, 54.4mm = US 7, 56.9mm = US 8, 59.5mm = US 9, 62.1mm = US 10.
5. The ring should slide on with slight resistance and come off with a little effort over the knuckle.
Method 3: Use a Ring Sizer
For the most accurate at-home measurement, use a plastic or metal ring sizer set. These are inexpensive ($5-10) and available online. Simply try on different sizes until you find the perfect fit. Many retailers (including Holycome) provide printable ring sizers — check our website for a downloadable version.
Tips for Accurate Sizing
Time of day: Fingers are smallest in the morning and largest in the evening. Measure at the end of the day for the most accurate fit.
Temperature: Cold shrinks fingers; heat/humidity swells them. Measure at room temperature.
Band width: Wide bands (6mm+) fit tighter. If measuring with a thin sizer for a wide band, go up 1/4-1/2 size.
Dominant hand: The dominant hand is usually slightly larger. Measure the actual hand the ring will be worn on.
Knuckles: If knuckles are large, size for the knuckle (the ring must pass over it). A ring that fits the base but won't pass the knuckle is too small.
Multiple measurements: Measure 2-3 times and average. If between sizes, choose the larger size (easier to resize down than up).
International Size Conversion
Ring sizes vary by country. US sizes use numbers (3-13). UK/Australia use letters (A-Z). Europe uses circumference in mm (40-76). Japan/China use numbers 1-27. Always confirm which system your customer is using. Holycome uses US sizes as standard but can accommodate any system — just let us know.
Surprise Engagement Sizing
For a surprise proposal: borrow one of their rings (worn on the same finger), trace the inside on paper, or bring it to a jeweler for measurement. If you can't borrow a ring, estimate based on height/weight (average women's size is 6-7, average men's size is 9-10). When in doubt, order slightly larger — resizing down is easier and less expensive than sizing up.
Resizing Information
Most rings can be resized 1-2 sizes up or down by a professional jeweler ($20-60). Eternity bands (stones all around) cannot be resized. Silver and gold resize well. If your ring doesn't fit, contact us about resizing options. Many retailers offer free resizing within 30 days of purchase.
Order custom-sized rings — we accommodate all sizes and international systems.