Ringa: Ring Sizer & Finder

Find your ring size on your phone, with a ring you already own or with your finger, and any bank card. No sign-up, no paywall: the full result is always free.

HOW IT WORKS
1. Calibrate once. Lay a bank card on the screen and match one line to its edge. Ringa learns the true size of your screen.
2. Measure. Place a ring that fits you on the screen and fit the circle to its inner edge. Smaller and Larger buttons fine-tune it by a tenth of a millimeter.
3. Read your size. The inner diameter in mm and your size in every common system, side by side.

Not sure what to do? Each step has a short animation that plays the first time, and How? shows it again.

NO RING AT HAND
Switch to With your finger. Lay the finger flat on the screen and mark the width at its root and at the knuckle. Ringa estimates your ring size to within one size and says so on the result. When you can, check it with a ring.

ONE MEASUREMENT, EVERY SIZE SYSTEM
US and Canada, UK and Australia (letters), Europe (circumference), Japan, Switzerland, India, Türkiye and inner diameter in mm. Handy when you shop from a jeweler abroad.

HONEST BY DESIGN
A phone screen is not a jeweler's mandrel. Ringa always shows the millimeters, says a ring measurement is accurate to about half a size, and suggests the larger size when you land between two. Tips cover the rest: measure in the evening, warm hands first, wide bands need half a size up.

SIZES FOR THE PEOPLE YOU LOVE
Save a result to yourself or to someone else and find it again in Settings under People. Planning a proposal or a gift? Borrow one of their rings for a minute, measure it and keep the size for the day you shop. Share the result with the jeweler in one tap.

PRIVATE
No account. Your calibration, people and sizes stay on your phone. 16 languages.

Ringa is free and supported by ads. At most one full-screen ad may appear after you confirm a measurement, before the result. There are no ads while you calibrate or measure, and the result is never locked.