Looking for a free ring size app to measure your finger without a printer or a piece of string? Get the real download links below for iPhone and Android, follow the step-by-step install guide for your device, or skip the app store entirely and size your ring right now in your browser.
Samsung Galaxy phone? Galaxy runs Android, so the Google Play button above installs the same way. Not ready to install anything? Use the instant web app now →
A dedicated ring size calculator app solves the two biggest problems with printed sizing guides: printer scaling errors, and having to track down a chart in the first place. Most ring sizer apps let you photograph a ring you already own, or place it directly on your phone's screen next to a calibrated reference circle — so the measurement comes from your own device instead of a page that may have printed slightly larger or smaller than intended.
Prefer the manual methods too? Our how to measure ring size guide covers the paper strip, string, and ring-tracing techniques step by step, and our international ring size chart lets you cross-check whatever number an app gives you.
Not sure how to download a ring size app? Follow the steps for your device below — it takes under a minute either way.
💡 Cross-check the result against our ring size chart before ordering, especially for gifts.
💡 Keep iPhone display zoom off and brightness at default — both can throw off on-screen sizing accuracy.
Prefer not to use a third-party store app at all? Our own web app already behaves like a native app — full screen, works offline once loaded, and adds an icon to your home screen — with no app store review wait and zero storage used. Here's how:
Most ring size apps use one of two approaches:
| Method | How it works | Common search terms |
|---|---|---|
| Camera / photo | Photograph a ring or finger next to a known-size object (coin, card); the app converts pixels to millimeters. | ring size camera app, ring size photo app |
| On-screen calibration | Calibrate the screen to a physical ruler once, then match a ring's inner edge to an on-screen circle. | app actual ring size chart on screen |
Both are estimation tools. For an engagement ring or any purchase over roughly $150, we recommend confirming with a jeweler's physical ring sizer before you order — see our measuring guide for backup methods that don't rely on a screen at all.
Both work. If you want a dedicated app icon and offline access, install Ring Sizer (iPhone) or Ring Fit (Android) using the links above. If you just need a size right now, the web app skips the install step entirely:
| Rings Sizes Web App | Store App (iOS / Android) | |
|---|---|---|
| Install required | No — works instantly | Yes, quick Play Store / App Store install |
| Storage used | 0 MB | Small, varies by app |
| Works on iPhone & Android | Same tool, both platforms | Separate apps per platform |
| Always up to date | Yes, automatically | Depends on user updating |
| Account required | None | Varies — check store listing |
| Home-screen icon | Yes, via Add to Home Screen | Yes, automatic |
Feature comparison based on publicly listed app details as of 2026; individual apps may vary — check each store listing for current permissions and pricing.
Calibrates to your exact device using a ruler you hold up to it — not a fixed image.
Match a digital circle to a ring's inner edge for an instant reading.
No ring on hand? Size directly from your finger circumference.
US, UK, EU, Japan, and Australia sizes shown together, instantly.
No sign-up, no email gate — open it and start measuring.
No premium tier, no paywall, no in-app purchases.
Yes. Ring Sizer by Jason Withers is available for iPhone on the App Store, and Ring Fit is available for Android on Google Play — both linked at the top of this page. If you'd rather not install anything, our web app does the same job in your browser.
It depends on your device: iPhone users get the most consistent results from Ring Sizer by Jason Withers, since it's built specifically for iOS. Android and Samsung Galaxy users can install Ring Fit from Google Play. Whichever you use, cross-check the result against our size chart before buying.
Yes — both apps linked on this page are free to download, and our own web app is completely free with no account, no premium tier, and no in-app purchases. Some third-party apps may offer optional in-app purchases, so check the store listing for current pricing.
A well-calibrated ring size app is typically accurate to within about a quarter size, similar to the paper strip or string method. Accuracy depends heavily on correct screen or camera calibration, so follow the app's calibration step carefully and re-measure once to confirm.
Yes — use our free online ring size calculator, which works directly in your phone or desktop browser with no download or account required.
Some retailers, including Hitched and jewelers like Gemporia and Tiffany, offer their own sizing guides or in-store sizing tools rather than a standalone downloadable app. If you're buying directly from a retailer, it's worth checking their site for a retailer-specific sizing tool in addition to a general-purpose app like the ones linked above.
Samsung Galaxy phones run Android, so today the same Google Play link above installs Ring Fit on a Galaxy phone the same way it does on any Android device — there's no separate Galaxy Store listing needed. Note this is different from the Samsung Galaxy Ring, a smart-ring wearable that Samsung sizes with its own official sizing kit rather than a standard jewelry ring size chart.
A dedicated Galaxy Store listing isn't live yet — leave your email and we'll let you know the moment it is. In the meantime, Samsung Galaxy phones can install the Android app from Google Play using the button above.
Guidance only — confirm with our free calculator for an exact fit.