# ThetaCalc vs RLM

The clearest difference is rating: RLM at 5.0 against ThetaCalc's 4.3. RLM also leads on update cadence (every 4 weeks vs every 3 months) and iOS requirement (15.0 vs 17.6). ThetaCalc's advantage is in-app purchases (none vs 1) and ratings volume (4 vs 1). On price, ads, monetization model and device support there is nothing between them.

Both are free to download. RLM sells 1 one-off in-app purchase. ThetaCalc asks for nothing beyond the download.

RLM holds the better App Store score, 5.0 against 4.3. Both are backed by a comparable volume of ratings — 4 and 1 respectively.

ThetaCalc ships an update every 3 months, RLM every 4 weeks. The most recent releases landed on October 29, 2026 and October 30, 2026 respectively.

## The numbers

| Metric | ThetaCalc | RLM |
| --- | --- | --- |
| Price | Free | Free |
| Rating | [4.3 (4 ratings)](https://appshunter.io/ios/app/thetacalc/id1521614636/reviews) | **[5.0 (1 ratings)](https://appshunter.io/ios/app/rlm-10cx/id6466089794/reviews)** |
| Number of ratings | **4** | 1 |
| Positive reviews | 100.0% of reviews | — |
| In-app purchases | **No** | Yes |
| Ads | No | No |
| Update frequency | Every 3 months | **Every 4 weeks** |
| Monetization | Free | Free |
| Size | 1 MB | 6 MB |
| Requires iOS | 17.6 | **15.0** |
| Devices | iPhone, iPad | **iPhone, iPad, iPod** |
| Age rating | 4+ | 4+ |
| Developer | [Felix Stehli](https://appshunter.io/developer/1521614638) | [R.L.M. Software](https://appshunter.io/developer/289639238) |

## What reviewers say

### ThetaCalc

[App page](https://appshunter.io/ios/app/thetacalc/id1521614636)

This utility app provides a Reverse Polish Notation (RPN) calculator. Users can extend its functionality by programming custom functions and equations using JavaScript.

**Highlights:** Reverse Polish Notation (RPN) calculator, User-programmable functions, JavaScript equation support, Extensible functionality

**Features:** macOS Compatibility

**In-app purchases:** none


### RLM

[App page](https://appshunter.io/ios/app/rlm-10cx/id6466089794)

This scientific calculator offers a comprehensive suite of tools for finance, business, statistics, and complex scientific calculations. It emulates a classic calculator while leveraging modern iOS device capabilities for ease of use and advanced functions.

**Highlights:** Finance and Business calculations, Date and Time interval calculations, Advanced Statistics and Curve Fitting, Complex Numbers and 3D Vectors, Unit and Currency Conversions, Equation Solver, Programmable functions

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

**In-app purchases (1)**

| Purchase | Price | Billing |
| --- | --- | --- |
| Lifetime Purchase | $9.99 | one-time |


## Frequently asked questions

### Is ThetaCalc free?

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

### Is RLM free?

RLM is free to download, with in-app purchases available.

### Which has better reviews, ThetaCalc or RLM?

RLM is rated higher. ThetaCalc averages 4.3 out of 5 from 4 ratings, while RLM averages 5.0 from 1 ratings.

### Do ThetaCalc or RLM have ads?

Neither ThetaCalc nor RLM shows ads.

### Which is updated more often, ThetaCalc or RLM?

ThetaCalc ships an update every 3 months, and RLM every 4 weeks. Most recently, ThetaCalc was updated on October 29, 2026 and RLM on October 30, 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.*