# O-Ring Size Finder — AS568 & metric from a photo

> AS568 & metric from a photo (iPhone/iPad app by Dmitriy Andrianov.)

- Source: https://appshunter.io/ios/app/o-ring-size-finder/id6822864756 (this page in markdown: same URL + `.md`)
- Developer: [Dmitriy Andrianov](https://appshunter.io/developer/1839682818)
- Category: Utilities, Productivity
- Price: Free with in-app purchases
- Age rating: 4+
- Requires: iOS 15.1 · 35 MB
- Languages: American English
- Released: 2026-11-05
- Data updated: 2026-11-06

## What is O?

Size an O-ring from one photo. Lay one ring flat next to a ruler or a widely recognized coin, shoot from above, and get a report you can take to a parts counter.

The report includes:
• Inside diameter, cross-section, and outside diameter
• The closest AS568 or metric size
• Compatible replacement sizes
• Other sizes the photo still allows
• How sure the reading is: high, medium, or low
• A parts-counter summary you can text or email

Made for mechanics, technicians, plumbers, and anyone replacing a seal when the package is gone.

A useful photo:
• One O-ring, lying flat, not stretched or stacked
• A metric ruler or a common coin in the same plane (US quarter, €1, or £1)
• Shot from directly above, in even light, on a plain background

A phone photo is not a caliper reading. Perspective and a slightly flattened ring can shift the size by a fraction of a millimeter. Confirm inside diameter and cross-section before ordering a seal for pressure, fuel, or other critical equipment. Material, such as NBR, FKM, or EPDM, cannot be read from a photo.

Free includes one successful size check every 24 hours. Premium is an auto-renewable subscription that removes the wait. Payment is charged to your Apple ID account at confirmation. The subscription renews unless you turn off auto-renew at least 24 hours before the end of the current period. You can manage or cancel the subscription in Settings > Apple ID > Subscriptions.

Your last 30 size checks stay on this device.

## Pricing and in-app purchases

Base price: Free.

**Subscriptions**

| Subscription | Price | Period |
| --- | --- | --- |
| Premium Weekly | $4.99 | per 7 days |
| Premium Yearly | $24.99 | per year |


## Is O safe?

Not enough ratings yet to assess O.

## Is O legit?

O-Ring Size Finder appears legitimate, with a few gaps. The AppsHunter Legitimacy Score for O is 65 out of 100 points across 7 verification signals from App Store and developer data.


## Version history (last 1 release)

### 1.0.0 — 2026-11-05

No release notes.

## More apps by Dmitriy Andrianov

- [PalQs: Social Poll & Vote](https://appshunter.io/ios/app/palqs-social-poll-and-vote/id6752524780)
- [Pesos to Dollars Conversion +](https://appshunter.io/ios/app/pesos-to-dollars-conversion-plus/id6761619021)
- [Euros to Dollars Conversion +](https://appshunter.io/ios/app/euros-to-dollars-conversion-plus/id6763568634)
- [Sunglasses Identifier: AI Scan](https://appshunter.io/ios/app/sunglasses-identifier-ai-scan/id6764140652)

All apps by Dmitriy Andrianov: https://appshunter.io/developer/1839682818

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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 2026-11-06.*