# RMS Calculator vs ProSITE

The clearest difference is price: ProSITE at Free against RMS Calculator's $1.99. ProSITE also leads on update cadence (every 5 weeks vs every 15 months). RMS Calculator's advantage is iOS requirement (12.0 vs 15.0). On ads, in-app purchases and device support there is nothing between them.

ProSITE is free to download; RMS Calculator costs $1.99 up front. Neither carries in-app purchases, so what you see is what you pay.

RMS Calculator ships an update every 15 months, ProSITE every 5 weeks. Both last shipped on October 27, 2026.

## The numbers

| Metric | RMS Calculator | ProSITE |
| --- | --- | --- |
| Price | $1.99 | **Free** |
| In-app purchases | No | No |
| Ads | No | No |
| Update frequency | Every 15 months | **Every 5 weeks** |
| Size | 8 MB | 290 MB |
| Requires iOS | **12.0** | 15.0 |
| Devices | **iPhone, iPad, iPod** | iPhone, iPod |
| Age rating | +4 | 4+ |
| Developer | [Kei Suefuji](https://appshunter.io/developer/1388335881) | [SMIE](https://appshunter.io/developer/976569921) |

## What reviewers say

### RMS Calculator

[App page](https://appshunter.io/ios/app/rms-calculator/id1511092361)

**Features:** macOS Compatibility, Vision Pro support

**In-app purchases:** none


### ProSITE

[App page](https://appshunter.io/ios/app/prosite/id1531318351)

**Features:** Vision Pro support

**In-app purchases:** none


## Frequently asked questions

### Is RMS Calculator free?

RMS Calculator costs $1.99, with no in-app purchases.

### Is ProSITE free?

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

### Do RMS Calculator or ProSITE have ads?

Neither RMS Calculator nor ProSITE shows ads.

### Which is updated more often, RMS Calculator or ProSITE?

RMS Calculator ships an update every 15 months, and ProSITE every 5 weeks. Most recently, RMS Calculator was updated on October 27, 2026 and ProSITE on October 27, 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.*