WP 31s vs DB40X
Price, ratings, monetisation and update history for both apps, side by side — with what reviewers say about each.
WP 31s
This app emulates a classic RPN scientific calculator, offering a rich function set for daily use with a simplified interface. It's based on the more complex WP 34s but is designed for easier operation.
- RPN scientific calculator emulation
- Rich function set
- Simplified, less cluttered keyboard
- Based on WP 34s
- Available on iOS
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WP 31s is a classic RPN scientific calculator based on the powerful but more complex WP 34s. Now available on iOS too (see the support site for other emulators and for the real stuff). It is not programmable but has a rich function set for daily use and is easier to use, thanks to a less cluttered keyboard. A manual can be downloaded at http://sourceforge.net/projects/wp34s/files/doc/Manual_wp_31s_1_2q.pdf/download
DB40X
A high-precision scientific calculator inspired by the HP48 series, offering arbitrary precision computations, complex numbers, vectors, matrices, and graphing. It supports RPN and algebraic operations, with over 1000 built-in functions and a hyperlinked help system.
- Arbitrary precision computations
- RPN and algebraic operations
- Complex numbers, vectors, and matrices
- Graphing and plotting
- Engineering units and conversions
- Hyperlinked help system
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DB40X is a high-precision scientific calculator compatible with DB48X and inspired by the legendary HP48 series from Hewlett-Packard. It is not an emulator, but a redesign from scratch, which is faster, and delivers never seen before capabilities like computations in arbitrary precision. Like the original HP48, DB40X supports an unlimited stack, RPN and algebraic operations, complex numbers, based numbers, vectors, matrices, text, symbolic computations, numerical solving and integration, graphing and plotting, statistics, engineering units, and well over 1000 built-in functions. DB40X adds several HP50G capabilities, including a library of equations and constants covering mathematics, physics or chemistry. Using modern technologies, DB40X goes well beyond the original HP48 in many ways: - It is significantly faster, uses less memory, and features a higher-resolution 240x400 pixels graphical display. - Integer and decimal values can have an arbitrarily large number of digits, so you can compute log(pi) with 200 digits in a few keystrokes. - The six function keys feature up to three function per key, giving quick access to up to 18 related functions at a time. - Complex numbers can mix and match polar and rectangular form. - Symbolic operations extend to complex numbers, vectors and matrices. - Based numbers can be in any base from 2 to 36, and support any number of bits, making it easy to emulate a 23-bit or 512-bit processor. - Text is represented using Unicode instead of the proprietary HP encoding, facilitating data exchange with the rest of the world. - Multiple graphs can be distinguished using bitmap patterns. - Engineering units include all the modern evolutions of the SI system, and can be configured by the user, e.g. to integrate currency units with the exchange rate du jour. Converting between USD/hour and EUR/day has never been so easy! - A built-in hyperlinked help system documents functions simply by holding the corresponding key, and combine a quick start guide, a user manual and a reference manual. DB40X will run many user RPL programs as is. However, since it is not an emulator, it will not run any HP binary object, and notably will not run HP48 games or anything involving system RPL. Version 0.7.14 is an early-access release. Please consult https://github.com/c3d/db48x/blob/stable/doc/5-Unimplemented.md for a list of HP48 commands that are not yet implemented. DB40X is part of a family of compatible RPL calculators that include DB48X and DB50X. DB40X lacks the ability to write programs or data to disk, and RPL programs are limited to 40K.
Screenshots
Verdict
WP 31s and DB40X both sit at 4.9 stars, but that hides the real split: 100% of WP 31s's written reviews are positive against 67% of DB40X's. WP 31s also leads on iOS requirement (12.0 vs 14.0). DB40X's advantage is update cadence (every 3 weeks vs every 10 months). On price, rating, ratings volume and ads 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
Both are free to download. Neither carries in-app purchases, so what you see is what you pay.
WP 31s holds the better App Store score, 4.9 against 4.7. Both are backed by a comparable volume of ratings — 15 and 7 respectively. Written reviews point the same way: 100% of WP 31s's written reviews are positive against 67% of DB40X's.
WP 31s ships an update every 10 months, DB40X every 3 weeks. The most recent releases landed on September 25, 2026 and October 3, 2026 respectively.
| Parameter | WP 31s | DB40X |
|---|---|---|
| Price | Free | Free |
| Rating | 4.9 (15 ratings) — better | 4.7 (7 ratings) |
| Positive reviews | 100.0% of reviews — better | 66.7% of reviews |
| Number of ratings | 15 — better | 7 |
| Update frequency | Every 10 months | Every 3 weeks — better |
| Ads | No | No |
| In-app purchases | No | No |
| Monetization | Free | Free |
| Devices | iPhone, iPad, iPod | iPhone, iPad, iPod |
| Requires iOS | 12.0 — better | 14.0 |
| Further details — not scored | ||
| Size | 16 MB | 7 MB |
| Age rating | 4+ | 4+ |
| Developer | Pascal Meheut | Christophe de Dinechin |
Customer experience
WP 31s
DB40X
In-app purchases
WP 31s
No in-app purchases
DB40X
No in-app purchases






