Ring sizing guides
Short, practical guides on getting ring size right. Why fingers swell and shrink, the average sizes for men and women, which rings a jeweler can resize, and how US, UK, and EU sizes compare.

Why size changes
Fingers swell and shrink with heat, salt, and the clock. Here is how much, and when to measure.
Read the guide
Resizing basics
Tungsten and full eternity bands often cannot be resized. See what can change, and by how much.
Read the guide
Women's sizes
Every US size from 3 to 10 in millimeters, the size jewelers sell most, and when a band width means sizing up.
Read the guide
Find your ring size
Own a ring, a finger, or a printer? Five accurate ways to find your size, plus when to size up.
Read the guide
Sizes by country
US numbers, UK letters, EU millimeters, German diameters, Japan numbers. One chart and the math that links them.
Read the guide
Men's sizes
Every US men's size in millimeters, plus the wide-band rule and how to size a comfort fit band.
Read the guide
Pandora sizes
The Pandora number is the millimeters. See 44 to 64 in US sizes, and when to take the bigger one.
Read the guide
Oura sizes
Oura numbers look like US sizes but do not measure like them. The Ring 4 chart in mm, and why the Gen3 ran tight.
Read the guide
Tiffany sizes
Tiffany uses plain US sizes. Every size from 3 to 13 in millimeters, how to use the printed sizer, and what resizes.
Read the guide
How a ring should fit
Snug at the base, a little push at the knuckle, no spinning. Six checks at home, and the fixes when a ring is off.
Read the guideReady to measure?
Skip the guesswork. The free sizer prints to true scale, with a ruler and a card check on the sheet so the number you read is the number you order.