# Uno Calculator vs Stack RPN Calculator

The clearest difference is rating: Uno Calculator at 4.6 against Stack RPN Calculator's 3.5. Uno Calculator also leads on review sentiment (73% vs 33%) and ratings volume (113 vs 2). Stack RPN Calculator's advantage is iOS requirement (11.0 vs 14.2). On price, ads, in-app purchases and monetization model there is nothing between them.

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

Uno Calculator holds the better App Store score, 4.6 against 3.5. That said, the two scores are not equally well evidenced: Uno Calculator has 113 ratings behind it against 2, so its average is the more settled of the two. Written reviews point the same way: 73% of Uno Calculator's written reviews are positive against 33% of Stack RPN Calculator's.

## The numbers

| Metric | Uno Calculator | Stack RPN Calculator |
| --- | --- | --- |
| Price | Free | Free |
| Rating | **[4.6 (113 ratings)](https://appshunter.io/ios/app/uno-calculator/id1464736591/reviews)** | [3.5 (2 ratings)](https://appshunter.io/ios/app/stack-rpn-calculator/id1493986697/reviews) |
| Number of ratings | **113** | 2 |
| Positive reviews | **73.2% of reviews** | 33.3% of reviews |
| In-app purchases | No | No |
| Ads | No | No |
| Update frequency | Every 5 months | — |
| Monetization | Free | Free |
| Size | 96 MB | 10 MB |
| Requires iOS | 14.2 | **11.0** |
| Devices | **iPhone, iPad, iPod, Mac** | iPhone, iPad, iPod |
| Age rating | 4+ | 4+ |
| Developer | [Uno Platform Inc.](https://appshunter.io/developer/1617866832) | [Dario Bersiga](https://appshunter.io/developer/668388549) |

## What reviewers say

### Uno Calculator

[App page](https://appshunter.io/ios/app/uno-calculator/id1464736591)

This app offers a comprehensive suite of calculation tools, handling everything from basic arithmetic to complex unit conversions. It supports measurements for size, temperature, speed, energy, and currency, making it a versatile solution for diverse needs.

**Highlights:** Arithmetic calculations, Unit conversions, Size measurements, Temperature conversions, Speed calculations, Energy calculations, Currency exchange

**In-app purchases:** none

**What reviewers like**

- 💰 Completely free with no ads or in-app purchases
- 🎨 Clean, minimalist, and intuitive user interface
- 🔧 Multiple calculator modes (standard, scientific, programmer)
- 📊 Useful unit conversion features
- 📜 Helpful history and memory panes for tracking calculations

**What reviewers complain about**

- ⌨️ No keyboard input support on Mac or iPad (major recurring complaint)
- 📍 Calculator buttons positioned on left side (inconvenient for right-handed users)
- 📜 History pane cannot be hidden or minimized
- ⏱️ Slower app launch time compared to stock calculator
- 🐢 Laggy performance on macOS with slow button responsiveness

**Reported bugs**

- Standard calculator mode doesn't follow order of operations (1+2*3 = 9 instead of 7)
- Buttons disappear while using on iPad
- Apple Pencil input causes buttons to blend into background
- Slow key responsiveness on macOS
- Numeric keypad input not recognized from Apple keyboard

**Requested features**

- Keyboard input support for Mac and iPad (most requested)
- Copy and paste functionality for results and formulas
- Option to reposition calculator buttons to right side
- Ability to hide or collapse history pane
- Persistent history that saves after app closes


### Stack RPN Calculator

[App page](https://appshunter.io/ios/app/stack-rpn-calculator/id1493986697)

This scientific calculator displays major functions on screen and utilizes a stack for calculations. It supports a stack of up to 4 values but can store many more numbers depending on device memory.

**Highlights:** Visible scientific functions, RPN (Reverse Polish Notation) input, Stack display for up to 4 values, Large number storage capacity, Designed for iPhone and iPad

**Features:** macOS Compatibility

**In-app purchases:** none


## Frequently asked questions

### Is Uno Calculator free?

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

### Is Stack RPN Calculator free?

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

### Which has better reviews, Uno Calculator or Stack RPN Calculator?

Uno Calculator is rated higher. Uno Calculator averages 4.6 out of 5 from 113 ratings, while Stack RPN Calculator averages 3.5 from 2 ratings.

### Do Uno Calculator or Stack RPN Calculator have ads?

Neither Uno Calculator nor Stack RPN Calculator shows ads.

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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.*