RingGauge: Ring Sizer
Calibrated ring size chart
Only for iPhone
Free · In‑App Purchases · Designed for iPhone. Not verified for macOS.
iPhone
RingGauge. Buy once. On-device.
Buying a ring online or as a surprise and not sure of the size? RingGauge finds the size of a ring that already fits, using a true-size printable chart or circles on your iPhone screen.
Print the ring size chart at 100%, check the scale against a real credit card, then lay the ring on the circles and pick the one that matches its inside edge. You can also calibrate your screen with a credit card and compare the ring against an on-screen circle.
• PRINTABLE SIZER PDF — a US Letter page with circles for 20 common sizes, from US 3 to 13, drawn at their true inside diameter.
• US, UK OR EU LABELS — switch the size system and the chart labels follow: US 3–13, UK F–Z1 or EU 44–70; the app also shows each size's diameter in mm.
• BUILT-IN SCALE CHECK — a true-size credit card outline on the chart shows at a glance whether your printer scaled the page.
• ON-SCREEN SIZER — slide a bar until it matches a real card's edge, then place the ring on the circle for the size you pick.
• PRINT, SHARE OR SAVE — print with AirPrint, share the PDF or save it to Files.
Honest scope: RingGauge measures a ring you already have; it does not measure a finger. Print with "fit to page" turned off and check the card outline — if it doesn't match a real card, the circles aren't true size. On screen you match the card's short edge, and the bar starts close to your iPhone's real scale, so a small nudge is usually all it takes. Sizes follow common retail charts and can differ slightly between jewelers and ring widths, so confirm with your jeweler before ordering something valuable.
Everything runs on your iPhone. Nothing is uploaded and no account is needed.
The on-screen sizer is free to use, and you can make 3 printable sizer PDFs for free. A one-time $4.99 purchase unlocks unlimited PDFs. No subscription, no ads.
Questions: overlapmarr@gmail.com
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Localized App Store screenshots for every language.
The developer, Jhomar Maravillas, indicated that the app’s privacy practices may include handling of data as described below. For more information, see the developer’s privacy policy .
Data Not Collected
The developer does not collect any data from this app.
Accessibility
The developer has not yet indicated which accessibility features this app supports. Learn More
Information
- Seller
- Jhomar Maravillas
- Size
- 687.1 KB
- Category
- Productivity
- Compatibility
Requires iOS 16.0 or later.
- iPhone
Requires iOS 16.0 or later. - Mac
Requires macOS 13.0 or later and a Mac with Apple M1 chip or later. - Apple Vision
Requires visionOS 1.0 or later.
- iPhone
- Languages
English and 5 more
- English, French, German, Japanese, Portuguese, Spanish
- Age Rating
4+
- 4+
- In-App Purchases
Yes
- Unlock Unlimited $4.99
- Copyright
- © 2026 RingGauge