# RPN vs HP16C

The clearest difference is price: HP16C at Free against RPN's $3.99. HP16C also leads on update cadence (every 8 days vs every 3 months) and rating (5.0 vs 4.6). RPN's advantage is ratings volume (17 vs 2) and iOS requirement (12.0 vs 17.0). On ads, in-app purchases and device support there is nothing between them.

HP16C is free to download; RPN costs $3.99 up front. Neither carries in-app purchases, so what you see is what you pay.

HP16C holds the better App Store score, 5.0 against 4.6. That said, the two scores are not equally well evidenced: RPN has 17 ratings behind it against 2, so its average is the more settled of the two.

RPN ships an update every 3 months, HP16C every 8 days. Both last shipped on September 21, 2026.

## The numbers

| Metric | RPN | HP16C |
| --- | --- | --- |
| Price | $3.99 | **Free** |
| Rating | [4.6 (17 ratings)](https://appshunter.io/ios/app/rpn-67-sd/id1109722386/reviews) | **[5.0 (2 ratings)](https://appshunter.io/ios/app/hp16c/id6761774728/reviews)** |
| Number of ratings | **17** | 2 |
| Positive reviews | 92.9% of reviews | — |
| In-app purchases | No | No |
| Ads | No | No |
| Update frequency | Every 3 months | **Every 8 days** |
| Monetization | Paid | **Free** |
| Size | 63 MB | 1 MB |
| Requires iOS | **12.0** | 17.0 |
| Devices | iPhone, iPod | iPhone, iPad |
| Age rating | 4+ | 4+ |
| Developer | [CuVee Software](https://appshunter.io/developer/424873503) | [Michael Doornbos](https://appshunter.io/developer/1891405652) |

## What reviewers say

### RPN

[App page](https://appshunter.io/ios/app/rpn-67-sd/id1109722386)

This app simulates a vintage programmable calculator from the mid-70s, offering enhanced features beyond the original. It allows users to run existing programs, manage virtual cards, and utilize advanced functions for scientific and engineering tasks.

**Highlights:** Virtual program and data cards, Virtual paper tape printer, Database-driven card manager, Create, label, and organize unlimited cards, Share cards via email, AirDrop, Dropbox, Editable program listings, Enhanced features for more program steps and registers

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

**In-app purchases:** none


### HP16C

[App page](https://appshunter.io/ios/app/hp16c/id6761774728)

This app faithfully recreates the legendary HP 16C Computer Scientist calculator, offering advanced hex arithmetic, bit manipulation, and base conversion. It features RPN, keystroke programming, and modern enhancements like a two-line display and haptic feedback.

**Highlights:** Full RPN calculator, Integer arithmetic (HEX, DEC, OCT, BIN), Configurable word size (1-64 bits), Complete bit operations, Keystroke programming, Two-line display, Haptic feedback

**Features:** macOS Compatibility

**In-app purchases:** none


## Frequently asked questions

### Is RPN free?

RPN costs $3.99, with no in-app purchases.

### Is HP16C free?

HP16C is free to download, with no in-app purchases.

### Which has better reviews, RPN or HP16C?

HP16C is rated higher. RPN averages 4.6 out of 5 from 17 ratings, while HP16C averages 5.0 from 2 ratings.

### Do RPN or HP16C have ads?

Neither RPN nor HP16C shows ads.

### Which is updated more often, RPN or HP16C?

RPN ships an update every 3 months, and HP16C every 8 days. Most recently, RPN was updated on September 21, 2026 and HP16C on September 21, 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.*