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Best Rpn Calculator Free Apps

218+ iOS apps curated and reviewed

4.4 avg rating
20 free apps
Updated June 2026

From beginner-friendly picks to power-user tools, our rpn calculator free list covers 218+ iPhone apps updated through June 2026. Compare ratings, prices, and screenshots in one place.

Compare top Rpn Calculator Free Apps (June 2026)

#AppPriceRatingAdsIn-App PurchasesUpdated
1Retro 15CRetro 15CFree4.3★ (212)NoNoJul 2026
2Free42Free42Free4.8★ (278)NoNoJul 2026
3iHP48iHP48Free4.7★ (270)NoNoJul 2026
4Calculator₊Calculator₊Free4.7★ (1.7M)YesYesJul 2026
5RLM-12CXRLM-12CXFree4.5★ (18)NoYesJul 2026
6bcRPNbcRPNFree4.8★ (4)NoNoMay 2026
7Stack RPN CalculatorStack RPN CalculatorFree3.5★ (2)NoNoMay 2026
8HP-35HP-35Free5.0★ (5)NoNoJul 2026

Top Picks for Rpn Calculator Free

Retro 15C#1

Retro 15C by Greg Hewgill

Editor's Choice
🔧 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
Free42#2

Free42 by Thomas Okken

HP-42S Calculator Simulator
Strong Contender
🔧 Utilities
4.8😊(278 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
iHP48#3

iHP48 by Alexis Lorca

The classic HP48 improved
Worth Considering
📊 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

More Rpn Calculator Free apps to explore

4
Calculator₊
Calculator₊
Calculator₊
Basic, Scientific, Plus Calc
Free

This app offers a comprehensive suite of calculation tools, including basic, scientific, and unit conversion functions. It features an AI-powered math solver that can solve problems from photos and a dedicated math notes section for jotting down equations and diagrams. Accessibility options like dynamic text size and VoiceOver support are also included.

Basic and scientific calculationsUnit and currency converterAI-powered math solver with photo recognition
🔧 Utilities
(1.7M)
free with in-app purchases
5
RLM-12CX
RLM-12CX
RLM-12CX
Finance & Business Calculator
Free

This app is a powerful financial and business calculator designed for iOS devices, replicating the functionality of the HP-12C with expanded features. It offers comprehensive tools for finance, business calculations, statistics, scientific functions, and unit conversions.

Finance and business calculationsAmortization schedulesBond price and yield calculations
💰 Finance
(18)
free with in-app purchases
6
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
7
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
8
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
9
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
(4.6K)
free with in-app purchases
10
PCalc Lite
PCalc Lite
PCalc Lite
The Best Calculator
Free

This free scientific calculator offers essential features like RPN mode, unit conversions, and multiple undo/redo. It provides a taste of a more powerful version, with optional in-app purchases for expanded functionality.

Optional RPN modeMultiple undo and redoUnit conversions and constants
🔧 Utilities
(214)
free with in-app purchases
11
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
(207)
free with in-app purchases
12
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
13
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
14
Calculator with History +
Calculator with History +
Calculator with History +
No ads & Scientific calculator
Free

This free calculator app offers a fast, ad-free experience with a visual input and calculation history. Customize your experience with various keyboard sounds and colors, and access advanced scientific functions when needed.

Ad-free experienceCalculation historyVisual input
💰 Finance
(23K)
free with in-app purchases
15
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
16
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
17
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
18
PowerOne calculator
PowerOne calculator
PowerOne calculator
Finance, scientific, and more
Free

This app offers a powerful calculator with hundreds of pre-built templates for finance, engineering, and more. Users can also create custom calculations for specific needs, ensuring accuracy and speed for repetitive tasks. Access your calculations across devices, online or offline.

Hundreds of pre-built calculation templatesCreate custom calculation templatesStandard and RPN calculator modes
🔧 Utilities
(748)
free with in-app purchases
19
WP 31s
WP 31s
WP 31s
by Pascal Meheut
Free

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 emulationRich function setSimplified, less cluttered keyboard
📊 Productivity
(15)
free
20
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

FAQ about Rpn Calculator Free

What are the best rpn calculator free apps for iPhone?
Retro 15C tops our rpn calculator free apps ranking as of June 2026, with a 4.3-star average from 212 App Store ratings, and it's free to download.
Retro 15C has no ads and has no in-app purchases, according to its App Store listing as of June 2026.
We track 218+ rpn calculator free apps on the iOS App Store as of June 2026, ranked by rating, recency, and analysis of real user reviews.
The Retro 15C app emulates a classic RPN (Reverse Polish Notation) scientific calculator. It offers a wide range of advanced mathematical functions, including complex number arithmetic, matrix calculations, numerical root finding, and integration.
Key features include complex number arithmetic and trig functions, matrix calculations, a numerical root finder, numerical integration, statistical functions with linear regression, and full programmability. It aims to replicate the functionality of classic 1980s RPN calculators.