Ring Sizer: Find Your Size

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Everyone
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Everyone
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Screenshot image

About this app

Measure a ring at true physical size, right on the screen. Calibrate once with any bank card, then lay a ring on the display and slide the circle until it meets the inside edge of the band.

HOW IT WORKS
• Match the on-screen outline to a bank card — every card is the same standard size
• Lay your ring on the screen and adjust the circle to the inside of the band
• Read out the US size and the inner diameter in millimetres
• Works fully offline — no account, no sign-up, nothing collected

Calibration is what makes the reading real: it teaches the app how large a millimetre is on your particular screen. Without calibrating, the size shown is only an estimate. Use it to narrow down a size, and confirm with a jeweller before you buy or resize a ring.

The free version covers the middle 7 US sizes. The one-time Premium Unlock opens all 21 sizes and keeps your calibration saved between sessions.
Measure your ring size on screen at true size — calibrate with a bank card.
Updated on
Aug 18, 2026

Data safety

Safety starts with understanding how developers collect and share your data. Data privacy and security practices may vary based on your use, region, and age. The developer provided this information and may update it over time.
  • No data shared with third parties
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  • No data collected
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What’s new

Initial release.
Content rating
Everyone
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App support

About the developer
펜타랩
rock@pentarab.com
대한민국 서울특별시 강남구 강남구 테헤란로 328, 1동 4층 402호(역삼동, 동우빌딩) 06212
+82 10-5124-2995

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