# Ring Sizer: Size & Convert — Measure on Screen, US UK EU

> Measure on Screen, US UK EU (iPhone/iPad app by heekyung moon.)

- Source: https://appshunter.io/ios/app/ring-sizer-size-and-convert/id6790018770 (this page in markdown: same URL + `.md`)
- Developer: [heekyung moon](https://appshunter.io/developer/6779193748)
- Category: Utilities, Lifestyle
- Price: Free
- Age rating: 17+
- Requires: iOS 16.4 · 52 MB
- Languages: American English
- Released: 2026-07-20
- Data updated: 2026-08-29
- User reviews in markdown: https://appshunter.io/ios/app/ring-sizer-size-and-convert/id6790018770/reviews.md

## What is Ring Sizer?

Find a ring size without a physical gauge. Ring Sizer lets you place a ring you already own on the screen, match it to an on-screen circle, and read the size — then convert it to every standard used around the world.

Accuracy comes from calibration: the app uses your device's screen size, and you can fine-tune it once by matching a standard bank card, so the circle on screen is true to life.

▶ Measure a ring
Place a ring on the screen, pinch or slide the circle to match its inside edge, and see the inner diameter in mm with US, UK, EU and JP sizes at once.

▶ Finger guide
Use the on-screen band as a width guide, or enter a circumference you measured with string or paper for a more reliable result.

▶ Convert any standard
Enter US, UK, EU, JP, inner diameter or circumference and get the full conversion, plus a complete size chart.

▶ Card calibration
Auto-calibrate from your device, then confirm with a bank card outline for a true-to-size circle, shown by an accuracy badge.

▶ Save sizes
Keep sizes for family and partners with name labels — perfect for gifts and surprise proposals.

On-screen results are estimates within about half a size and depend on calibration, so confirm at a jeweler before ordering. Finger width is not the same as circumference; the string method is more accurate. Works offline, no account needed.


## Version history (last 4 releases)

### 1.2.1 — 2026-08-03

Performance improvements, bug fixes, and refinements for the latest iOS.

### 1.1.1 — 2026-07-30

Performance improvements, bug fixes, and refinements for the latest iOS.

### 1.1 — 2026-07-28

Performance improvements, bug fixes, and refinements for the latest iOS.

### 1.0 — 2026-07-21

No release notes.

## More apps by heekyung moon

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- [Golden Hour Sun Tracker](https://appshunter.io/ios/app/golden-hour-sun-tracker/id6779194270)
- [GIF Maker & Editor Studio](https://appshunter.io/ios/app/gif-maker-and-editor-studio/id6779194430)
- [Slow Shutter Long Exposure](https://appshunter.io/ios/app/slow-shutter-long-exposure/id6780141566)
- [Rain Alert Nowcast](https://appshunter.io/ios/app/rain-alert-nowcast/id6780142286)

All apps by heekyung moon: https://appshunter.io/developer/6779193748

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*Data collected daily from the US App Store and indexed by [AppsHunter](https://appshunter.io/). User reviews are verbatim App Store reviews. Ratings, prices and chart positions refresh continuously; this snapshot is from 2026-08-29.*