Ring Size Guide
A ring should slide over the knuckle with a little resistance and sit comfortably at the base of the finger. Use the size finder, measure a ring you already own right on your screen, print our sizer, or read the full conversion chart — every ring we craft is offered in quarter sizes.
Size Finder
Enter a measurement you already have — or a size from another country — and we’ll translate it into a US ring size and every common equivalent.
Measure a Ring on Your Screen
Have a ring that already fits the right finger? Calibrate your screen with any standard bank or ID card, then match the circle to the inside edge of your ring.
Calibrate. Hold a standard-size card (85.6 × 54 mm) flat against the screen and drag the slider until the dashed outline matches the card’s edges.
Match your ring. Lay your ring on the circle and adjust until the circle’s edge just meets the inside of the band.
Your ring measures size 7. Send to Size Finder
International Ring Size Conversion Chart
US sizes from 3 to 13 in quarter steps, with inside diameter and circumference in millimeters and the closest UK/Australian, European (ISO) and Japanese sizes.
| US / Canada | Diameter (mm) | Circumference (mm) | Diameter (in) | UK / AU | EU / ISO | Japan |
|---|
Measurements follow the standard US scale (each whole size ≈ 0.81 mm in diameter, ≈ 2.55 mm in circumference). UK, EU and Japanese sizes are the closest match and can vary slightly between makers.
Three Ways to Measure
Print Our Sizer
A printable sheet with actual-size circles and a paper strip sizer.
- Print at 100% (no “fit to page”).
- Check the 50 mm line with a ruler.
- Lay a ring on the circles, or cut out the strip and wrap it.
String or Paper
Works with whatever you have in a drawer.
- Wrap string or a thin paper strip around the base of the finger.
- Mark where it overlaps — snug, not tight.
- Measure in millimeters and enter it in the Size Finder.
A Ring You Own
The most reliable method if the ring fits the intended finger.
- Measure straight across the inside, edge to edge.
- Enter the diameter in the Size Finder.
- Or use Measure on Screen.
Getting the Fit Just Right
Measure late in the day. Fingers are slightly larger in the evening and in warm weather, and smaller when cold.
Mind the knuckle. If your knuckle is wider than the base of your finger, measure both and choose a size between them.
Wide bands fit snugger. For bands 6 mm and wider, consider going up a quarter to a half size.
Measure three times. Take readings on different days and go with the most consistent result.
Dominant hand runs larger. Size the exact finger and hand the ring will be worn on.
Between sizes? Choose the larger quarter size — a ring that’s a touch loose is safer than one that won’t pass the knuckle.
Ring Size FAQ
What is the average ring size?
The average ring size for women in the US is about a size 6 to 7, and the average ring size for men is about a size 9 to 10. Because fingers vary widely, we recommend measuring rather than relying on an average.
Does American Pearl offer quarter sizes?
Yes — American Pearl offers every ring in quarter sizes (for example 6, 6.25, 6.5 and 6.75), so you can choose the size between two half sizes instead of rounding.
How do I find my ring size without a ring sizer?
You can find your ring size without a ring sizer by wrapping a strip of paper or string around the base of your finger, marking where it overlaps, measuring that length in millimeters, and entering it into the Size Finder above. You can also measure a ring you already own on your screen.
Should I size up for a wide band?
Yes, you should usually size up for a wide band: rings 6 mm and wider cover more of the finger and feel tighter, so going up a quarter to a half size is often more comfortable. Our specialists can help you decide for a specific design.
How do I measure a ring size as a surprise?
To measure a ring size as a surprise, borrow a ring the person already wears on the same finger and measure its inside diameter, or trace its inside edge on paper. Friends and family can often confirm the size, too.
Can a ring be resized after purchase?
Many rings can be resized after purchase, but some designs — such as eternity bands, tension settings and certain intricate pavé — are difficult or impossible to resize. Please call our specialists at 1-800-847-3275 before ordering if you are unsure of the size.
Still unsure of your size?
Our pearl specialists are happy to help — toll-free 1-800-847-3275.