i41CX vs DB40X
Price, ratings, monetisation and update history for both apps, side by side — with what reviewers say about each.
i41CX
This app offers a powerful RPN scientific calculator experience, functionally equivalent to a renowned model. It provides extensive memory registers, over 300 built-in functions, and programmability. Advanced features can be unlocked via in-app purchases.
- RPN logic with 4-element stack
- 319 main and 124 extended memory registers
- Over 300 built-in functions
- Programmable up to 2000 lines
- User-definable keyboard
- Bluetooth keyboard support
- Device integration features
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i41CX is the same powerful advanced programmable RPN scientific calculator as the highly acclaimed i41CX+ but without the latter’s incredibly advanced capabilities such as the printer, expansion, CAS, etc. It is functionally equivalent to the world-renowned HP-41CX and inherits all of the i41CX+ usability features including extremely responsive and animated key clicks, audible key feedback sounds, optimally spaced keys for accurate input, traditional and upbeat modern diverse set of skins, etc. If you are looking for a powerful programmable RPN scientific calculator but don’t need all of the capabilities of i41CX+ then i41CX is for you. And best of all, if you ever decide that you need the more advanced capabilities of i41CX+ you can enable them using secure in-app purchases right within the app! FEATURES: • RPN logic with a 4 element deep memory stack • 319 main and 124 extended memory registers • Over 300 built-in functions, including nearly 100 functions created specifically for i41CX • Time, calendar, alarm, and stopwatch functions • Rich set of functions and algorithms: numerical, mathematical, statistical, and much more • Access to the entire HP-41 library of solutions for science, mathematics, statistics, engineering, business, financial, surveying, medicine, real estate, and many other domains • Programmable - Over 2000 lines • User definable keyboard • Ability to operate the calculator using a Bluetooth keyboard • Device integration: external display mirroring, copy and paste, GPS, accelerometer, digital compass, time and date synchronization, and much more • iOS 8 Notification Center widget • Sound support including synthetic tones and interface sounds • Support for calculator skins and optional mini stack display • Adjustable sound volume and display colors • Usage & Examples table with usage tips and examples • Quick reference guide of all built-in functions • Beautiful and clean user interface *********************************************************** A comprehensive FAQ is available at http://alsoftiphone.com/i41CX. Please don't hesitate to use the "Contact Us" link there if you cannot find the answers or information that you seek. Thank you.
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
The clearest difference is price: DB40X at Free against i41CX's $7.99. DB40X also leads on in-app purchases (none vs 4). i41CX's advantage is review sentiment (90% vs 67%) and chart position (#188 vs unranked). On rating, update cadence, ads and device support 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
DB40X is free to download; i41CX costs $7.99 up front. i41CX sells 4 one-off in-app purchases. DB40X asks for nothing beyond the download.
On the App Store both sit at effectively the same score — 4.6 for i41CX against 4.7 for DB40X. That said, the two scores are not equally well evidenced: i41CX has 45 ratings behind it against 7, so its average is the more settled of the two. Written reviews are what separate them: 90% of i41CX's written reviews are positive against 67% of DB40X's.
i41CX ships an update every 5 weeks, DB40X every 3 weeks. The most recent releases landed on September 30, 2026 and June 4, 2026 respectively.
| Parameter | i41CX | DB40X |
|---|---|---|
| Price | $7.99 | Free — better |
| Rating | 4.6 (45 ratings) | 4.7 (7 ratings) — better |
| Positive reviews | 90.5% of reviews — better | 66.7% of reviews |
| Number of ratings | 45 — better | 7 |
| Update frequency | Every 5 weeks | Every 3 weeks — better |
| Ads | No | No |
| In-app purchases | Yes | No — better |
| Monetization | Free with in-app purchases | Free — better |
| Best chart rank | #188 — better | — |
| Devices | iPhone, iPad, iPod | iPhone, iPad, iPod |
| Requires iOS | 15.0 | 14.0 — better |
| Further details — not scored | ||
| Size | 135 MB | 7 MB |
| Age rating | 4+ | 4+ |
| Developer | Antonio Lagana | Christophe de Dinechin |
Customer experience
i41CX
DB40X
In-app purchases
i41CX
- Overlays Upgrade$2.99
- Printer Upgrade$3.99
- CAS Upgrade$7.99
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- i41CX+ Features Upgrade$17.99
DB40X
No in-app purchases









