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Best Rpn Calculator Free Apps

249+ iOS apps curated and reviewed

4.3 avg rating
19 free apps
Updated August 2026

From beginner-friendly picks to power-user tools, our rpn calculator free list covers 249+ iPhone apps updated through August 2026. Compare ratings, prices, and screenshots in one place.

Compare top Rpn Calculator Free Apps (August 2026)

#AppPriceRatingAdsIn-App PurchasesUpdated
1iHP48iHP48Free4.7★ (270)NoNoAug 2026
2Free42Free42Free4.8★ (283)NoNoAug 2026
3Retro 15CRetro 15CFree4.3★ (212)NoNoJul 2026
4RPN Calculator freeRPN Calculator freeFree1.0★ (1)NoNoAug 2026
5Stack RPN CalculatorStack RPN CalculatorFree3.5★ (2)NoNoMay 2026
6No Equal RPN CalculatorNo Equal RPN CalculatorFree4.9★ (7)YesNoMay 2026
7The Best Calculator - Calc ProThe Best Calculator - Calc ProFree4.6★ (4.7K)YesYesAug 2026
8RePNCalc - RPN Calculator ProRePNCalc - RPN Calculator ProFree5.0★ (1)NoYesMay 2026

Top Picks for Rpn Calculator Free

iHP48#1

iHP48 by Alexis Lorca

The classic HP48 improved
Editor's Choice
📊 Productivity
4.7😊(270 ratings)
Free
iHP48 screenshot 1
iHP48 screenshot 2
iHP48 screenshot 3
iHP48 screenshot 4
iHP48 screenshot 5

This app brings the powerful HP48 calculator experience to your mobile device. It offers enhanced performance, seamless file management, and a customizable interface with support for various HP calculator models. Enjoy a familiar and convenient calculator solution without needing extra hardware.

What We Love

  • 🚀 Excellent emulation of HP48
  • 👍 Familiar and nostalgic feel
  • 👍 Comprehensive functionality
  • 👍 Customizable skins

Room to Improve

  • 🐛 Occasional crashes or freezes
  • 🐛 Missed keystrokes when typing quickly
  • 🐛 Blank or flickering display
Free42#2

Free42 by Thomas Okken

HP-42S Calculator Simulator
Strong Contender
🔧 Utilities
4.8😊(283 ratings)
Free
Free42 screenshot 1
Free42 screenshot 2
Free42 screenshot 3

This application is a faithful re-implementation of the HP-42S scientific calculator and its associated printer. It offers full functionality without requiring original HP ROM images and is an open-source project.

What We Love

  • 🚀 Faithful reproduction of HP42S
  • 👍 Identical to physical calculator
  • 👍 Runs all original programs
  • 👍 Convenient to have on phone

Room to Improve

  • 🐛 Screen not filling entire display on newer devices
  • 🔇 Configurable key click sound missing
  • 🔇 Lack of loud click sound feedback
Retro 15C#3

Retro 15C by Greg Hewgill

Worth Considering
🔧 Utilities
4.3😊(212 ratings)
Free
Retro 15C screenshot 1
Retro 15C screenshot 2

This app emulates a classic RPN scientific calculator, offering advanced features like complex number arithmetic, matrix calculations, and programmability. It provides a functional and complex tool reminiscent of 1980s calculators.

What We Love

  • 🚀 Lightning-fast calculator
  • 👍 Authentic look and feel of HP 15C
  • 🚀 Faster than real HP 15C
  • 👍 Excellent RPN emulation

Room to Improve

  • 🐛 Doesn't save settings, programs, or memory
  • 🐛 No key press feedback or sound
  • 🐛 Blinking display issue with large calculations

More Rpn Calculator Free apps to explore

4
RPN Calculator free
RPN Calculator free
RPN Calculator free
by Benjamin Pisano
Free

This utility app offers a scientific calculator with Reverse Polish Notation (RPN) mode for faster calculations. Its simple interface is designed for engineers and scientists, providing efficient computation on iPhone devices.

Scientific calculator functionsReverse Polish Notation (RPN) modeFast calculation
🔧 Utilities
(1)
free
5
Stack RPN Calculator
Stack RPN Calculator
Stack RPN Calculator
by Dario Bersiga
Free

This scientific calculator displays major functions on screen and utilizes a stack for calculations. It supports a stack of up to 4 values but can store many more numbers depending on device memory.

Visible scientific functionsRPN (Reverse Polish Notation) inputStack display for up to 4 values
📊 Productivity
(2)
free
6
No Equal RPN Calculator
No Equal RPN Calculator
No Equal RPN Calculator
by Stan Corbin
Free

This scientific calculator utilizes Reverse Polish Notation (RPN) for efficient complex calculations, mirroring the functionality of classic HP calculators. It features a continuously visible stack for better tracking and includes 10 memory registers, plus a dedicated quadratic equation solver.

Reverse Polish Notation (RPN)Always visible stack10 memory registers
🔧 Utilities
(7)
ad-supported
7
The Best Calculator - Calc Pro
The Best Calculator - Calc Pro
The Best Calculator - Calc Pro
10 Powerful Calculators
Free

This app offers a comprehensive suite of 10 powerful calculators and 10 financial worksheets, designed to handle everything from basic arithmetic to complex scientific and financial calculations. It includes features like unit conversion, currency exchange, graphing, and statistical analysis, making it a versatile tool for students and professionals.

10 powerful calculators (Standard, Scientific, Graphing, etc.)10 financial worksheets (Mortgage, Loan, Compound Interest, etc.)Unit Converter with 3000+ conversions
🔧 Utilities
(4.7K)
free with in-app purchases
8
RePNCalc - RPN Calculator Pro
RePNCalc - RPN Calculator Pro
RePNCalc - RPN Calculator Pro
Easy Reverse Polish Notation
Free

This utility app offers a Reverse Polish Notation (RPN) calculator experience for iOS devices. It features customizable key layouts via swipe gestures and long-press options for stack items. External keyboard support is also available.

Reverse Polish Notation (RPN) inputSwipe gesture key layout customizationLong-press stack item options
🔧 Utilities
(1)
free with in-app purchases
9
R47 RPN Calculator
R47 RPN Calculator
R47 RPN Calculator
HP Program Editor & Tutorials
Free

This scientific calculator uses Reverse Polish Notation (RPN) to help you break down complex problems. It offers a full 47-series instruction set with advanced functions and a program editor. The free version includes extensive tutorials and documentation.

RPN scientific calculator47-series instruction setProgram editor
📚 Education
(23)
freemium
10
Complex RPN Calculator
Complex RPN Calculator
Complex RPN Calculator
Complex Numbers RPN Calculator
Free

This scientific calculator utilizes a four-level stack and natively handles complex numbers. It allows users to input and view numbers in both polar and rectangular formats, remembering its state and offering 10 memory locations.

Complex number supportFour-level stackPolar and rectangular formats
🔧 Utilities
(22)
free
11
RPN-70 SD
RPN-70 SD
RPN-70 SD
Very rare vintage calculator
Free

This app is a faithful simulation of a rare 1974 financial calculator, offering all its original functions with enhanced features like more memory registers and a visual stack display. It's designed for users who appreciate vintage technology and need precise financial calculations.

Photo-realistic vintage calculator designFull HP-70 function simulationAnimated keys with sound
📊 Productivity
(11)
free
12
Touch RPN calc
Touch RPN calc
Touch RPN calc
Financial/Sci RPN calculator
Free

This app offers a powerful RPN calculator with financial and scientific functions, mimicking popular industry-standard models. It includes programming capabilities and expandable flavors for diverse calculation needs.

RPN financial calculatorRPN scientific calculatorProgramming functions
💰 Finance
(208)
free with in-app purchases
13
Stackis RPN
Stackis RPN
Stackis RPN
RPN Calculator
Free
$0.99 | 100% OFF

A calculator designed for users who prefer Reverse Polish Notation (RPN). It offers a familiar interface for RPN users and includes support for duodecimal calculations.

RPN calculation styleDuodecimal (dozenal) supportFamiliar interface for RPN users
🔧 Utilities
(2)
free
14
r.Calc
r.Calc
r.Calc
by Nicolas Jorand
$0.99

A straightforward calculator utilizing Reverse Polish Notation (RPN) for everyday calculations. It offers a four-level visible stack with a total capacity of 100 positions, providing visual feedback on stack fullness. Basic arithmetic operations and stack manipulation functions are included.

Reverse Polish Notation (RPN) inputFour visible stack levels100-position stack capacity
🔧 Utilities
(3)
paid
15
RPN Memory Calculator
RPN Memory Calculator
RPN Memory Calculator
RPN Multi Function Calculator
Free

This application provides a straightforward reverse Polish notation (RPN) calculator with essential functions and memory operations. It also includes integrated unit conversions for various measurements, allowing for quick conversions directly within the app. The calculator remembers your session, preserving all registers and memory values for future use.

Reverse Polish Notation (RPN) inputSeven core calculator functionsMemory operations
📚 Education
(0)
free
16
Rpn Calculator SW
Rpn Calculator SW
Rpn Calculator SW
Rpn Calculator
Free
🔧 Utilities
(0)
17
RPN Big Float Calculator
RPN Big Float Calculator
RPN Big Float Calculator
by Stephan Jancar
Free

This advanced calculator offers unparalleled precision for complex mathematical operations, supporting up to 100,000 digits. It features both RPN mode and direct formula input, with a vast array of functions and built-in constants. Explore calculations with complex numbers, quaternions, and p-adic numbers.

High precision up to 100,000 digitsRPN and direct formula input modesComplex number and quaternion calculations
📚 Education
(1)
free
18
HP-35
HP-35
HP-35
RPN Calculator. HP-35, 45, 21
Free

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 emulationHP-35 modelHP-45 model
🔧 Utilities
(5)
free
19
bcRPN
bcRPN
bcRPN
by Paul Wilkins
Free

This utility app functions as a Reverse Polish Notation calculator. It handles complex numbers and utilizes extended precision for all calculations, offering an unlimited stack depth and an undo feature for up to 10 operations.

Reverse Polish Notation (RPN) inputComplex number calculationsExtended precision math
🔧 Utilities
(4)
free
20
SimpleCalc - Calculator
SimpleCalc - Calculator
SimpleCalc - Calculator
Calculator
Free
🔧 Utilities
(0)

FAQ about Rpn Calculator Free

What are the best rpn calculator free apps for iPhone?
iHP48 tops our rpn calculator free apps ranking as of August 2026, with a 4.7-star average from 270 App Store ratings, and it's free to download.
iHP48 has no ads and has no in-app purchases, according to its App Store listing as of August 2026.
We track 249+ rpn calculator free apps on the iOS App Store as of August 2026, ranked by rating, recency, and analysis of real user reviews.
iHP48 is a mobile application that revives the classic HP48 calculator experience. It provides enhanced performance and convenience, allowing users to access powerful calculator functions directly on their device without needing a physical calculator.
Key features include support for multiple HP calculator models (HP38, HP39, HP48, HP49, HP50), enhanced user experience with haptic feedback and zoom options, seamless file management for transferring and accessing calculator objects, and access to a comprehensive library of calculator packages and ROMs.