Online ring sizer

BetaScreens differ in size and zoom, so a ring drawn on screen means nothing until the screen is calibrated. First match a standard bank card, then match the inside edge of a ring that already fits.

This sizer has not yet been validated against physical devices. Treat its reading as an estimate and confirm with a physical sizer or jeweller before ordering anything you cannot return.

On-screen sizing is in Beta

Screen sizing depends on your display being calibrated accurately, and this feature has not yet been validated across real devices. Use it for a starting point, not for a ring that cannot be resized or returned.

Step 1 — Calibrate with a payment card

Hold any standard bank or ID card flat against the screen. Drag the corner handle, or use the slider, until the outline matches the card exactly. Every ID-1 card is 85.6 mm wide.

Drag the round handle to resize, or pinch with two fingers.

Card outline width

Current scale: 3.78 screen pixels per millimetre.

Keyboard: focus the slider and use the arrow keys for single-pixel adjustments.

If you cannot use the visual sizer

The visual match depends on seeing and dragging on screen. If that is not practical, measure the ring's inside diameter with a ruler and enter it in the ring size calculator, or use a physical sizer — both are stronger evidence than any on-screen method.

Calibration is reset when the screen changes

Rotating the device, zooming the page or moving to another display changes how many pixels make a millimetre, so the saved calibration is discarded and you will be asked to calibrate again. Calibration stays on this device only.