# O vs Thread Calculator

The clearest difference is ads: O at none against Thread Calculator's shown. O also leads on update cadence (every 6 weeks vs every 18 months) and iOS requirement (12.0 vs 15.0). On price, in-app purchases and device support there is nothing between them.

Both are free to download. Neither carries in-app purchases, so what you see is what you pay.

O ships an update every 6 weeks, Thread Calculator every 18 months. Both last shipped on September 9, 2026.

## The numbers

| Metric | O | Thread Calculator |
| --- | --- | --- |
| Price | Free | Free |
| Rating | — | **[4.3 (13 ratings)](https://appshunter.io/ios/app/thread-calculator/id1559560290/reviews)** |
| Number of ratings | — | **13** |
| Positive reviews | — | 33.3% of reviews |
| In-app purchases | No | No |
| Ads | **No** | Yes |
| Update frequency | **Every 6 weeks** | Every 18 months |
| Monetization | — | Ad-supported |
| Size | 40 MB | 25 MB |
| Requires iOS | **12.0** | 15.0 |
| Devices | iPhone, iPad, iPod | iPhone, iPad, iPod |
| Age rating | 4+ | 4+ |
| Developer | [HUTCHINSON](https://appshunter.io/developer/862345826) | [GSR Gustav Stursberg GmbH](https://appshunter.io/developer/1559560292) |

## What reviewers say

### O

[App page](https://appshunter.io/ios/app/o-ring/id1229032846)

**Features:** macOS Compatibility

**In-app purchases:** none


### Thread Calculator

[App page](https://appshunter.io/ios/app/thread-calculator/id1559560290)

This app provides a quick and easy way to calculate thread dimensions for various units, including tap hole sizes and bolt specifications. It helps metalworkers find precise measurements for internal and external threads without consulting tables.

**Highlights:** Thread cutting calculator for multiple units, Cold forming calculator, Thread repair calculator, Tap hole and bolt diameter calculation, Saves time compared to tables

**Features:** macOS Compatibility

**In-app purchases:** none


## Frequently asked questions

### Is O free?

O is free to download, with no in-app purchases.

### Is Thread Calculator free?

Thread Calculator is free to download, with no in-app purchases.

### Do O or Thread Calculator have ads?

Thread Calculator shows ads; O does not.

### Which is updated more often, O or Thread Calculator?

O ships an update every 6 weeks, and Thread Calculator every 18 months. Most recently, O was updated on September 9, 2026 and Thread Calculator on September 9, 2026.

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*Compared by [AppsHunter](https://appshunter.io/) from daily US App Store data. Review summaries are generated from verbatim App Store reviews.*