allRPNCalc Calculator

allRPNCalc Calculator

  • Category: Finance
  • Release Date: 2019-02-01
  • Current Version: 4.2
  • Adult Rating: 4+
  • File Size: 1.79 MB
  • Developer: Ernest Brock
  • Compatibility: Requires iOS 11.0 or later.
  • Rating Count: 47


allRPNCalc is a versatile calculator that uses the powerful Reverse Polish Notation logic system combined with an automated 4 level stack to compute answers to complex mathematical problems. The keyboard layout and display have been optimized for use on an iPhone,iPod Touch and iPad. Large keys with sound feed back give you typing confidence and the last function keyed is always displayed. Functions are logically laid out to eliminate multiple key entry for most problems. Display: Results are displayed in fixed, fraction, scientific or engineering notation with from 0 to 14 significant digits displayed. In programmer’s mode hex, decimal, octal or binary (with windowing) can be displayed. Calculations are carried out in industry standard IEEE double format with 14+ significant digits and exponents ranging +/-308. Math: +, -, ×, ÷, ln, log, e^x, 10^x, y^x, x², x³, 1/x, √x, ∛x, fraction part, integer part, absolute value, random, seed, mod Trigonometry: sin, cos, tan, asin, acos, atan, sinh, cosh, tanh, asinh, acosh, atanh, to radians, to degrees, to rectangular, to polar, to hours, to hours minutes seconds, hours minutes seconds add and subtract, triangle solver, π, π/2. Trig functions can be computed in radians, degrees or gradians. Statistics: sum plus, sum minus, mean, weighted mean, standard deviation, population standard deviation, linear estimate x, y and correlation coefficient, combination, permutation, factorial (gamma), percent, delta percent, percent of total Programer’s functions: and, or, xor, not, shift left, shift right, rotate left, rotate right, word sizes 8, 16, 32, 48 Conversions: 47 world currencies and over 100 commonly used metric, english and other conversion factors used in scientific, engineering and financial calculations. Financial: time value of money calculations, n, i, pv, pmt, fv, depreciation (straight line, sum-of-years, declining balance), bond price and yield to maturity, amortization, net present value, internal rate of return, up to 80 cash flows, days between dates, date plus days, rounding. Storage: 4 level automatic stack with lastX, exchange and roll down, 20 general purpose storage registers, register arithmetic +,-,×,÷ , 6 dedicated registers for statistics, 80 cash flow entries, 5 financial registers.



  • Love this app

    By K Housen
    Really nice if you’re used to RPN calculators. I use it daily.
  • The only calculator you’ll ever need

    By gus_42
    Seriously. Whatever this calculator doesn’t do, I don’t need. Thanks so much for such an excellent product.
  • AllRPNCalc

    By MedPhys49
    For my needs, this is the best rpn app I’ve used.
  • Super duper awesome in all the right ways

    By CryptoHobbit
    Comprehensive features, intuitive settings, and a natural user interface. Well thought out and developed calculator. Thank you!
  • Outstanding RPN calculator...

    By Neptue
    If you like HP calculators, this app should serve you well. I have been using this calculator for years, and it remains one of my all time favorites. It takes a successful HP calc and adds several useful features: unit conversions, currency exchange rates. I also value its ability to perform scientific and financial calculations. I have tried and used more than 20 calculator apps. Some do offer features not in this one. However, it is in my top two calculator apps. So glad the developer has updated this app to be compatible with current iOS versions. Hope other legacy app developers will do the same. The fear of losing this one kept me from being willing to update to the latest iOS. UPDATE: Been using this great app for years, and it never lets me down! Kudos to the developers who have kept this app working throughout all the many iOS changes by Apple.
  • Best RPN Calculator

    By Hungstart
    For us RPN fans that cut our teeth on the HP RPN calculators years and years ago, i.e., HP 41/43/63, this is your iPhone RPN calculator.
  • Best one

    By reverse-Pole
    Does it all, excellent interface and operations
  • User

    By DonHM
    I like this implementation of RPN. Would be nice if there were a native iPad version — that somehow took advantage of the larger screen.
  • Hp-12c +++++

    By Byrrno
    For those of us who grew up using Reverse Polish Notation, RPN is built into our hand. This little calculator app is easy to use, and has many more features than the HP-12C. Weight and volume conversion is often really useful, and it's easy here. Currency conversion! Get updated conversion rates with a couple taps. I've been using this great app for about 7 generations of iPhones.
  • allRPNCalc is best one out there

    By Katainasia
    I've tried most of the HP calcs for iphone. This is the most intuitive interface and includes super helpful conversions, including currencies. Love it. Thanks for updating!!
  • Love the app

    By PithCA
    Really nice app. Has as many features as one could reasonably ask for and is very easy to use. Good implementation of RPN, just like HP calculators back in the day.
  • Works great, except

    By CharlieS3
    I’ve been using this app for many years and find it great as a financial and general calculator. I calculate loan payments routinely. It has always worked great. However , recently I looked at an amortization chart and could not exit the chart. Stopping and restarting the app did not clear it. I had to restart iOS to get back to the main page. Please fix!
  • allRPNCalc - the best

    By MP35217
    I have bought very few apps for my phone. The purchase of allRPNCalc is the exception. I spent a few dollars on this several years ago and it is the best use of money for an accessory ever. A powerful RPN calculator, that does everything I need and more. It is regularly updated to keep it in sync with all the updates iOS undergoes. I highly recommend this app to anyone that needs an RPN calculator. You will not find better.
  • Great RPN calculator

    By J. A. Young
    I use it all the time!
  • Great RPN calculator!

    By The Meerkat
    I used to work for the HP calculator division that pioneered RPN. Trust me. This is beyond a full featured RPN machine. Well thought out. Great job! Each version is even better than last. Now at v4.1. Very happy customer.
  • Excellent

    By SaidWhatToo
    Been using for years. All the functionality plus more. Never a crash.
  • Great RPN Calc!

    By Sean702
    Calculations are spot-on and this developer has been kind enough to provide free updates for many years now... Which makes it well worth buying. I've tried others and I still like this one the best. Very easy to use yet it has the depth and breadth you'd expect. I use it frequently for mortgage calculations and amortizations.
  • Great program!

    By Comsguy
    This is a great RPN app! It works very well and the developer support is exemplary! I had an issue with iOS 11 update and the response to my inquiry was swift and simple. Way more than I’d expected for a $6.00 application. Others should emulate this fine example! Well done Mr. Brock, thank you.
  • Great rpn calculator

    By MRR714
    Couldn’t do without it
  • RPN Rules

    By Xetdog
    RPN rules and this is the calculator to do the job
  • Had it since the original. Use it. Love it.

    By Big2thumbs
    This has been one of my most used apps over the years. It's had very few if any updates - because it hasn't needed them, until this latest OS release. I was sad to see a notification that this RPN calc wouldn't work anymore. I'm now happy that this new updated version came out. My only suggestions are to make the stack longer and to add 'mils' in the conversions.
  • Must have RPN

    By Red69Chevy
    I grew up using RPN, and have no interest in ever learning algebraic entry, so this app is a lifesaver.
  • Love it

    By mafpolo
    Excellent app. So convenient. I don't have to carry my HP17 anymore
  • Nice RPN calculator.

    By lm6068
    This has my "go to" calculator for years. The new version is nice improvement,
  • Love it

    By acebiz
    This calculator is a real buy at this price. I love all the choices and the ability to get foreign currency quotes. I used to use RPN notation and then lost my HP calculator. This machine is really slick. I couldn't live without it.
  • It's like having my HP back in my hand

    By MPT23
    Live it. RON logic is the way to go.
  • Comprehensive and easy to use

    By Bob Buchanan
    Have been using RPN calculators since mid 70's. This is thorough, seems complete, straight forward, logical, and easy to use.
  • One of the best

    By Love RPN
    I looked around for quite a while for a good RPN calculator. Then I found this one! I have it on my first page of apps. It's my goto calculator. Very satisfied.
  • Excellent app.

    By JCO90
    If you are used to RPN calculators, this is the app for you. I used an HP 48G for years and struggled with online calculators. This app. Was an answer to my concerns. Works like a 48G.
  • Love it

    By Matt in Florida
    I've been using my HP15C and RPN since longer than my current students have been on the planet. This was one of the very first apps I purchased when I got my phone a few years back. Great app. Thanks to the developer for the free update. Highly recommended.
  • You need this app!

    By Mad_Scrabbler
    If you are a professional in any field which requires complex calculations, you need this app. I use it constantly.
  • Great app!

    By Xword Lover
    Can't think of anything else I'd like it to do.
  • Glad to see the update!

    By Fosh59
    I have been using this RPN calculator for a number of years and I love it! Great for engineering calculations, conversions and financial. I was worried that you might not update to be compatible with new operating system. Glad you made the effort! Great calculator!
  • Best RPN calculator

    By krsing99
    Thank you for the update. The look of the interface is beautifully done and the app will live on! Been using this app for years and it was breaking my heart that it might not survive the next iOS update. I think all of the changes are excellent, and yet the look and feel of the calculator are maintained. Thank you, and keep up the great work.
  • Best ever calculator

    By bogeytune
    Love it. Use it everyday. Get it now if you like RPN
  • Useful update to an excellent app

    By Fan of RPN
    The help button (?) is well thought out as is the calculator. I've installed a number of calculatotrs and removed most but there are two calculators that i will not remove: allRPNCalc and PCalc. If you want to transition from an algebraic calculator to an RPN calculator, start with PCalc and when you are comfortable install allRPNCalc. By the way, RPN is a superior logic system because when you press an operator button (+, -, X, /, square root, sine, cosine,...) an operation takes place immediately. That is not the case with an algebraic system. Sometimes an operation is delayed, sometimes it takes place immediately.
  • RPN

    By Chappell's iPhone
    Use it all the time. Excellent app.
  • Thank you for the update

    By Bluesdaddy2
    This is a great calculator that I've been using for a few years now. I've tried many others but this is my go to. Very glad to see the 64 bit upgrade. I was getting worried it might left behind. Thank you.
  • What just happened

    By CRT Design
    I love this APP!!! Best on the market. I go to use it this morning and it says I have demo version and to buy a legal copy......I bought a legal copy ORIGINALY and have been using it for at least 2 years....I even tried to buy another copy but the App Stores shows it as already purchased and won't let me...I'm stuck............HELP
  • Without question the best!!!!

    By nomavestor
    I am a finance student who currently works in a bank. I am constantly calculating various financial figures. In college, I used the TI 32 financial and a HP 30B business pro. This calculator is WAY better than either of them! It has a graphing feature, as well as amortization tables...not to mention it has 4 other forms of calculators to toggle between. Buying a new HP 30b costs about $60! this app IS TOTALLY WORTH THE PRICE (especially compared to the name-brand fin. calc apps)!
  • Have Learned RPN? You NEED This!

    By Aardvark1917
    I cut my calculator teeth on an HP-34c, upgraded at one point to an HP-32sII, and bought an HP-48g days before they were discontinued. Though the allRPNCalc cannot graph (that would be an awesome update, if developed) nor offer stepwise programming, it has plenty of numerical oomph to satisfy most calculation problems, including those of binary, octal, and hexadecimal. iPad users note: this is an iPhone/iPodTouch oriented app that must be viewed in portrait mode to operate.
  • Wow! Best Calc Ever (stunning reviews by all who understand it)!

    By DASreview
    This is the BEST CALCULATOR APP EVER! I recently heard from developer that this is a niche product and was so disappointed that people don't understand the gem that is here. I have personally owned HP-12c, HP-48gx, HP-35, HP-17BII, HP41CX, TI-84plus, and TI-30 calculators and this one is vastly better than all of them. It has excellent functionality in SCI, FIN, STAT, PROG and General MATH areas, is super easy to use (well organized keyboard that is not crowded), has great output, and a few hidden benefits like conversions, curve fitting (super easy), etc. This app is only for those who know how to use RPN (includes all of you HP-12C users), or who care to learn how to use it, as opposed to the more difficult Algebraic logic found on most calculators. If you understand order of operations and find nested parentheses tedious than you should be using RPN, if you are not already. Historically, Hewlett Packard developed high end professional engineering and financial calculators with RPN logic while Texas Instruments developed low end student calculators with Algebraic logic. In retrospect, TI stole the show by getting to the students first; a peverse outcome given the superiority of RPN. HP screwed up and we all lost in the process. To be fair, Algebraic logic calculators have markedly improved in recent years, but RPN is so much better for day to day and this calculator's implementation is sensational. This is your chance to right a historical wrong. Support RPNby using the finest example of its capabilities, allRPN Calc, and in the process you will be supporting a superior app developer (returned my email regarding a problem with this great product virtually within minutes) in a sea of mediocrity. The cream should rise to the top, but only if we as users share our finest discoveries. Since I am so enamored with this app, I offer one final plug. If you are using ANY other RPN calculator on your iPhone or as a stand alone, you will be so very happy after you try this app out. It is the consumate bargain.
  • Superb multi-functions with a usable interface.

    By Let's Be Objective
    Although I have a different preference in the placement of the keys (I prefer an HP41 layout with the operand keys to the left of the numeric keys) and there is no programmability to this calculator, for what it can do and for the relative ease of being able to do it, I give this app five stars.
  • Richwolski

    By Rysiu618
    I tried a few rpn apps and this one (the last) is it, has a practical layout and is easy to toggle between modes. Also the "look" is great, similar to Apple's built in calc (keys) - a personal preference. Great job!!
  • Don't leave home without it

    By Siriusguy
    I consider the program of the MOST valuable ones on my iPhone...and wouldn't leave home without it. My wife doesn't understand why I need RPN for routine math, not to mention financial calculations, trig functions and statistics...but I do! When a recent "update" glitch, now resolved, left me without the program for several weeks, I realized how much I missed it, as I found myself trying to open it several times a day. Ultimately, getting it again operative, once I found the instructions on the developer's website, proved ridiculously quick and easy. A particularly nice feature for the Financial section is its nearly automatic generation of a full amortization or depreciation schedule. The one feature I would like to see in the next version would be operation in both the current vertical but also, the horizontal mode, the latter the way one uses the fabled HP11C and HP12C, which I have in the hardwired versions, but which I no longer carry, as allRPNCalc makes them superfluous, rather like a DC-3 in an Airbus 380 era.
  • Most comprehensive

    By RPN Fan
    I have tried a bunch of the RPN calculators and this is the easiest to use and most comprehensive of them. This is the one you will end up using most of the time, so save time and start with this one.
  • Pros: Excellent layout/colors. 2-line visible RPN stack! Multiple function sets

    By meclizine50mg
    After searching for and downloading/paying for several RPN calculators, and as a previous user of the HP-48sx back in engineering college and the HP-32SII back in medical residency, allRPNcalc (version 2) is the first RPN calculator that deserves a spot on the front page of my iPhone as a worthy replacement of the functionality and feel of my still-functioning HP calculators. The overall design/layout/colors are well-planned, efficient, and basically beautiful - I keep turning on my iPhone just to look at allRPNcalc, which is an impressive demo app when showing off the features of the iPhone. Finally - an RPN calc with TWO levels of the (four-level) stack displayed! Why don't more RPN calcs do this? I would prefer seeing all 4 levels, but 2 is significantly better than 1. Plus you could always use the roll "R" button or press the information "i" button to see a full list of the stack and registers. And finally - a large "Enter" button! It seems the developers took all of the basic functionality of the old HP RPN calculators, but instead of simply duplicating appearance and multiple shift keystrokes and limited displays (as many other RPN apps do), they smartly modernized it to the iPhone platform.     Additional features include display of the last operation in the upper right of the screen, easy change of the display output mode (including fractions) using the top green buttons, a triangle solver, built in help that lists the functions of all the keys, and unit conversions (including currencies) with an interesting scroll-wheel interface. The information "i" button is in an odd location, but makes more sense when you realize that the bottom 5 rows of grayish buttons are fixed. The top three rows of brown buttons change their function depending on the "mode", selected by the row of green buttons. I do not use the financial features enough to make any comment on those available functions.     Although I agree with many suggestions of the reviewers below, I am giving allRPNcalc 5 stars for design and functionality. Suggestions: A reviewer below suggested an "undo" function ("last x" can be helpful but won't preserve y) - how about implementing undo by swiping finger across the number display? As a possible solution for displaying all four levels of the stack, how about pressing and holding the number display will trigger a small window that pops up (same red on black, small font like the stack/registers list) quickly showing t,z,y,x, and then disappears when your finger lets go.
  • Great app; even better support

    By john dunham
    If you grew up using HP RPN calculators, this is the calculator for you. It's exactly what you'd expect. And more. But even more important. I ran into a snag, emailed the developer, and had a response *in minutes*!! Was up and running minutes after that. For a $6 product, that's amazing. I'm such a fan, it's hard to put into words.
  • Wonderful!

    By bmk5140
    Best calculator in the app store.