Comparison

RPN vs DB50X

Price, ratings, monetisation and update history for both apps, side by side — with what reviewers say about each.

Head to head
About

RPN

This app is a detailed simulation of a 1973 scientific calculator, offering a photorealistic interface and all original functions. It includes powerful enhancements for modern use, such as complex number support and advanced date calculations.

Highlights
  • Photorealistic calculator simulation
  • Full HP-45 function implementation
  • Complex number support
  • Advanced date and time functions
  • Printer simulation for calculation records
  • Stopwatch functionality
  • Cut/copy/paste display values
Features
Read full description

RPN-45 SD is a complete simulation of the scientific hand-held calculator HP-45 from 1973. Powerful enhancements turn the calculator into an amazingly useful tool for the 21st century. Features: • Photo-realistic look based on an existing device • Original LED display or high-contrast LCD display • Printer to keep a record of calculations • Animated keys with adjustable click sound and visual feedback • Simulation of the HP-45's computation times (may be disabled) • All functions and operations of the HP-45 fully implemented • "Secret" stopwatch implemented, extensible from 12 to 100 hours capacity • Stopwatch may be preset to current time • Swipe left across display to correct wrong number entries • Cut/copy/paste of display value • Tap display to show stack and all memory registers • Complex numbers may be used in almost all operations • Non-volatile stack and registers • 18 storage locations (9 in complex number mode) • Exponentiation and factorial accept any values (incl. complex) • Optional hyperbolic functions • Logarithm to any base (incl. complex) • Solve linear equations in two or three unknowns • Solve quadratic and cubic equations • Normal distribution, Pearson correlation coefficient of paired variables • Linear regression with estimates • Weighted mean • Permutation, Combination (binomial coefficient) • Integer and fractional part of a number • Display rounding • Random numbers in any range, integer or real • Day of the week of any date between Jan 1, 0001 and Dec 31, 9999 • Easter date for any year between 1583 and 4099 • Support for Julian dates • Date and day of the week a number of days away (past or future) • Number of days between any two dates • Last Stack operation • Show display value in hexadecimal • Percentage of sum • Register arithmetic includes summation registers and LAST x • Indicators for active prefix keys • Angular mode indicator • Localized decimal point • Thousand's separator • Clear all registers • Backup registers in a protected area Double-tap the display for some basic hints. Also available for iPad (RPN-45 HD). For more information, a manual and sample calculations visit the RPN-45 website: cuveesoft.ch/rpn45/en What users said: "Have been using HP RPN calculators since HP-35 first came out. The CuVée versions for Apple products are the best emulations by far. I have, and regularly use, them all." "This app is a great emulator of the classic HP-45 Scientific Calculator, in look, feel and function. It keeps getting better and better with each update." "This is the most like the real thing that I've used. I've bought others but keep coming back to this App. It's photorealistic, the LEDs appear the way the real ones do, and the buttons almost give the same satisfying feedback of the real thing."

About

DB50X

This scientific calculator offers high-precision computations with arbitrary precision for numbers. It supports advanced functions like complex numbers, matrices, symbolic calculations, and graphing, with a user-friendly interface and extensive built-in help.

Highlights
  • Arbitrary precision calculations
  • RPN and algebraic operations
  • Complex numbers, vectors, matrices
  • Symbolic and numerical solving
  • Graphing and plotting
  • Engineering units and constants
  • Unicode text support
Features
Read full description

DB50X is a new high-precision scientific calculator inspired by the legendary HP50G 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 HP50G, DB48X 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. It integrates a library of equations and constants covering mathematics, physics or chemistry. Using modern technologies, DB50X goes well beyond the original HP50G in many ways: - It is significantly faster, uses less memory, and features a higher-resolution 240x400 pixels graphical color 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 colour 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. - Over 700K of memory is available for RPL programs. - Access to iCloud to save your program and edit them from your Mac. DB508X will run many user RPL programs designed for the HP48, HP49 or HP50 directly as is. However, since it is not an emulator, it will not run any HP binary object, and notably will not run HP50G games or anything involving system RPL. This is an early-access release. Please consult https://github.com/c3d/db48x/blob/stable/doc/5-Unimplemented.md for a list of commands that are not yet implemented. DB50X is part of a family of related calculators that include the black-and-white DB48X and the entry-level DB40X.

Screenshots

RPN4 screens
DB50X4 screens

Verdict

The call

The clearest difference is rating: DB50X at 5.0 against RPN's 4.3. DB50X also leads on update cadence (every 3 weeks vs every 4 months) and review sentiment (100% vs 82%). RPN's advantage is price ($1.99 vs $9.99) and iOS requirement (12.0 vs 14.0). On ratings volume, ads, in-app purchases and monetization model 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

CostPrice · In-app purchases · Ads · Monetization

RPN costs $1.99 and DB50X $9.99 up front. Neither carries in-app purchases, so what you see is what you pay.

ReceptionRating · Positive reviews · Number of ratings

DB50X holds the better App Store score, 5.0 against 4.3. Both are backed by a comparable volume of ratings — 15 and 9 respectively. Written reviews point the same way: 82% of RPN's written reviews are positive against 100% of DB50X's.

UpkeepUpdate frequency

RPN ships an update every 4 months, DB50X every 3 weeks. The most recent releases landed on November 10, 2026 and November 8, 2026 respectively.

Scorecard5 real differences · 5 level
RPN versus DB50X: the parameters behind the verdict, then further details
ParameterRPNDB50X
Price$1.99 — better$9.99
Rating4.3 (15 ratings)5.0 (9 ratings) — better
Positive reviews81.8% of reviews100.0% of reviews — better
Number of ratings15 — better9
Update frequencyEvery 4 monthsEvery 3 weeks — better
AdsNoNo
In-app purchasesNoNo
MonetizationPaidPaid
DevicesiPhone, iPodiPhone, iPad, iPod — better
Requires iOS12.0 — better14.0
Further details — not scored
Size14 MB7 MB
Age rating4+4+
DeveloperCuVee SoftwareChristophe de Dinechin

Customer experience

RPN

All ratings15 ratings
Positive80.0%
Neutral0.0%
Negative20.0%
Written reviews11 reviews
Positive81.8%
Neutral0.0%
Negative18.2%

DB50X

All ratings9 ratings
Positive100.0%
Neutral0.0%
Negative0.0%
Written reviews5 reviews
Positive100.0%
Neutral0.0%
Negative0.0%

In-app purchases

None

RPN

No in-app purchases

None

DB50X

No in-app purchases

Questions

Is RPN free?
RPN costs $1.99, with no in-app purchases.
Is DB50X free?
DB50X costs $9.99, with no in-app purchases.
Which has better reviews, RPN or DB50X?
DB50X is rated higher. RPN averages 4.3 out of 5 from 15 ratings, while DB50X averages 5.0 from 9 ratings.
Do RPN or DB50X have ads?
Neither RPN nor DB50X shows ads.
Which is updated more often, RPN or DB50X?
RPN ships an update every 4 months, and DB50X every 3 weeks. Most recently, RPN was updated on November 10, 2026 and DB50X on November 8, 2026.

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