ONLINE RING SIZER
Find a likely ring size using a ring that already fits.
Calibrate the screen with a card or coin, match the ring's inner edge, and get an estimate in millimeters and Brazilian size. Free, with no camera or account.
USE ON SCREEN
Three steps to reach a useful reference.
Calibration accounts for screen differences. If the device rotates or the window changes size, the sizer asks you to calibrate again.
Step 1 of 3
Everything happens on this screen.
START HERE
Choose a physical reference
You will resize the shape on screen until it matches a real object. No card data is read or sent.
BEFORE BUYING
An at-home measurement helps. Confirmation still matters.
Ring size is a purchase reference, not a fit guarantee. Band width and shape also make a difference.
- Measure a familiar ring
Use a round ring that feels comfortable on the same finger and hand.
- Match only the inner edge
The ring's outside thickness is not part of the diameter used by the sizer.
- Check the jeweler's chart
Brands and designs can vary slightly. Confirm in person before an important purchase.
COMMON QUESTIONS
What to know about measuring a ring on your phone.
Can a phone measure ring size?
Yes. After calibrating the screen with an object of known size, place a ring over the circle. The result remains an estimate.
Does the sizer use the camera?
No. It relies on the calibrated on-screen size and never asks for camera access.
Can I measure my finger with string?
This tool is designed for a ring that already fits or a known millimeter measurement. String and paper can stretch or tighten and increase error.
What should I save?
Keep the likely size with the diameter, person, finger and date. That context is more useful than a number alone.
CONTINUE IN THE APP
Google Play
App Store