On-screen ring sizer
Measure a ring you already own, right on your screen. Calibrate once with a credit card, then match the circle to the inside of your ring.
Step 1 - Calibrate your screen
Lay a credit or ID card flat on the box below - long side across - and drag the slider until the box is exactly the size of your card (85.6 x 54 mm).
Calibration: - · · saved
Step 2 - Measure your ring
Place a ring you own flat on the screen, then drag the circle's edge (or use the slider) until it sits just inside the band.
No ring to measure? Use the paper-strip method or the printable sizer. Measure · Print
Frequently asked questions
How does an on-screen ring sizer work?
First you calibrate the screen using a standard credit card (85.6 mm wide) so the page knows your display's real size. Then you place a ring you own on the screen and resize the on-screen circle until it matches the ring's inside.
Is an on-screen ring sizer accurate?
With careful calibration it is accurate to roughly a quarter size. Screens vary, so the credit-card calibration step is essential. For an engagement or non-resizable ring, confirm with a jeweler.
Do I need to install anything?
No. It runs in your browser, with no app and no sign-up. You can add it to your home screen to use it offline.
Prefer paper? Use the printable sizer. Have a measurement already? Try the converter. Print · Converter