# PrimeCalc vs kong calculator

The clearest difference is update cadence: kong calculator at every 4 days against PrimeCalc's every 5 weeks. PrimeCalc's advantage is iOS requirement (12.0 vs 15.0). On price, ads, 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.

PrimeCalc ships an update every 5 weeks, kong calculator every 4 days. The most recent releases landed on November 2, 2026 and November 3, 2026 respectively.

## The numbers

| Metric | PrimeCalc | kong calculator |
| --- | --- | --- |
| Price | Free | Free |
| In-app purchases | No | No |
| Ads | Yes | Yes |
| Update frequency | Every 5 weeks | **Every 4 days** |
| Size | 12 MB | 20 MB |
| Requires iOS | **12.0** | 15.0 |
| Devices | iPhone, iPad, iPod | iPhone, iPad, iPod |
| Age rating | 4+ | 4+ |
| Developer | [Yutaka Nakao](https://appshunter.io/developer/1303008060) | [Changyeol Seo](https://appshunter.io/developer/551904752) |

## What reviewers say

### PrimeCalc

[App page](https://appshunter.io/ios/app/primecalc-modprime-factor/id1332239791)

**Features:** macOS Compatibility

**In-app purchases:** none


### kong calculator

[App page](https://appshunter.io/ios/app/kong-calculator/id1594969449)

**Features:** macOS Compatibility

**In-app purchases:** none


## Frequently asked questions

### Is PrimeCalc free?

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

### Is kong calculator free?

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

### Do PrimeCalc or kong calculator have ads?

Both PrimeCalc and kong calculator show ads.

### Which is updated more often, PrimeCalc or kong calculator?

PrimeCalc ships an update every 5 weeks, and kong calculator every 4 days. Most recently, PrimeCalc was updated on November 2, 2026 and kong calculator on November 3, 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.*