Measure a ring you already own directly on your device. To ensure perfect accuracy, we require a quick credit-card calibration step before showing you the virtual sizing circles.
Because every phone and monitor has a different pixel density, a digital ring sizer is completely useless without calibration.
Hold a standard credit card (which is universally 85.6mm wide) against your screen and adjust the slider below until the box perfectly matches the width of your card.
Place your existing ring flat on the screen over the circles below. Find the circle that perfectly touches the inside edge of your ring. You should be able to see the colored circle, but no white space inside the ring.
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Evelyn is a certified GIA Gemologist with over a decade of experience in fine jewelry sizing and design. She ensures all conversion charts and measuring advice strictly adhere to ISO 8653 standards.