Ring Size Finder

converter

Measure your ring size directly on screen: place a real ring on the interactive circle, or enter your finger circumference. Calibrate using an ATM/credit card. Supports US, UK, JP, VN.

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How to use

  1. 1(Optional) Click "Calibrate Screen" and place a real ATM card to measure accurately
  2. 2"Measure Ring" tab: Drag the slider until the circle matches your real ring
  3. 3"Finger Circumference" tab: Wrap thread around your finger, enter the length in mm
  4. 4View your US, UK, Japan, and VN ring sizes

Frequently Asked Questions — Ring Size Finder

How accurate is online ring size measurement?+

It can be very accurate if you calibrate your screen using a real ATM card first. Calibration corrects for your screen actual pixel density (PPI), ensuring physical size calculations are correct.

What is a standard ATM card size?+

ATM/credit cards follow ISO 7810 ID-1 standard: 85.6mm × 53.98mm. This is universally consistent, making it perfect for screen calibration.

What does US ring size 7 correspond to?+

US Size 7 = inner diameter 17.35mm = circumference 54.5mm ≈ Japanese size 13 ≈ UK size O½. Always try a physical ring when possible, as ring width can affect perceived size.

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