x36 vs HP
Price, ratings, monetisation and update history for both apps, side by side — with what reviewers say about each.
x36
This app offers a powerful scientific and engineering calculator with advanced features like programmability, multiple number bases, and statistical functions. It emulates the functionality of calculators from the 70s and 80s, providing over 100 functions for complex calculations.
- Programmability with 1000 steps
- Trigonometric functions with selectable units
- Statistical functions and linear regression
- Four number bases (Decimal, Hex, Octal, Binary)
- Metric-English conversions
- Fraction operations
- Over 100 functions
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This calculator is packed with features common to any good scientific and engineering calculator from the 70's and 80's including: Programability. Can store up to 1000 steps. Includes label, jump, loop and subroutine capability. -Common mathematical operations including square roots, powers, reciprocals, and logarithmic functions. -Up to 15 levels of parenthesis. -A full set of trigonometric functions working with user selectable units of degrees, radians, and gradians. Also performs polar-rectangular and degrees-minutes-seconds - decimal degree conversions. -Common physical constants such as the speed of light, gravitational constant and Avogadro's number. -Single and double variable statistical functions including linear regression. 10 memory storage locations. -Metric-English and English metric conversions. -Four number bases (Decimal, Hexadecimal, Octal, and Binary). -Bit logic operations. -Three display modes (floating point, scientific, and engineering) with user adjustable number of digits displayed. -Can perform operations with fractions! Over 100 functions in all! AND NO ADS!
HP
Emulates classic Hewlett Packard RPN scientific calculators from the 1970s. Experience the original HP-35, HP-45, and HP-21 models on your iPhone.
- RPN calculator emulation
- HP-35 model
- HP-45 model
- HP-21 model
- Classic scientific calculator interface
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The classic Hewlett Packard RPN (Reverse Polish Notation) calculators. - HP-35, HP-45. First pocket scientific calculators (1972). - HP-21. 2nd gen of the HP-35 (1975)
Screenshots
Verdict
The clearest difference is price: HP at Free against x36's $0.99. HP also leads on update cadence (every 11 days vs every 2 months) and ratings volume (5 vs 1). x36's advantage is device support (3 vs 1) and iOS requirement (12.0 vs 17.2). On rating, review sentiment, ads and in-app purchases there is nothing between them.
Scored on Price · Rating · Positive reviews · Number of ratings · Update frequency · Ads · In-app purchases · Monetization · Best chart rank · Devices · Requires iOS
HP is free to download; x36 costs $0.99 up front. Neither carries in-app purchases, so what you see is what you pay.
On the App Store both sit at effectively the same score — 5.0 for x36 against 5.0 for HP. That said, the two scores are not equally well evidenced: HP has 5 ratings behind it against 1, so its average is the more settled of the two. Written reviews split almost evenly too, at 100% and 100% positive.
x36 ships an update every 2 months, HP every 11 days. Both last shipped on October 8, 2026.
| Parameter | x36 | HP |
|---|---|---|
| Price | $0.99 | Free — better |
| Rating | 5.0 (1 ratings) | 5.0 (5 ratings) |
| Positive reviews | 100.0% of reviews | 100.0% of reviews |
| Number of ratings | 1 | 5 — better |
| Update frequency | Every 2 months | Every 11 days — better |
| Ads | No | No |
| In-app purchases | No | No |
| Monetization | Paid | Free — better |
| Devices | iPhone, iPad, iPod — better | iPhone |
| Requires iOS | 12.0 — better | 17.2 |
| Further details — not scored | ||
| Size | 1 MB | 2 MB |
| Age rating | 4+ | 4+ |
| Developer | Carl Cook | Enrique Haro |
Customer experience
x36
HP
In-app purchases
x36
No in-app purchases
HP
No in-app purchases
