Comparison

RPN Calculus vs ReadableCalc

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

Head to head
About

RPN Calculus

This scientific calculator app for iPad offers a clean RPN interface with basic and advanced functions. It supports high precision calculations and provides an extensive, user-extendable database of scientific constants.

Highlights
  • RPN (Reverse Polish Notation) interface
  • Basic and advanced mathematical functions
  • High precision calculations (up to 15 digits)
  • Extensive scientific constant database
  • User-extendable constant database
  • Memory space for values
Read full description

RPN Calculus is a scientific RPN Calculator for the Apple iPad. RPN Calculus provides basic arithmetic operations as well as advanced mathematic operations like trigonometric, hyperbolic or logarithmic functions. The calculator app provides an unlimited, well, limited by system resources, amount of memory space for values. RPN Calculus performs calculations with a precision of up to 15 digits and supports a number range from -1E127 to 1E127. It's smallest presentable number is 1E-128. RPN Calculus offers a clean and simple layout, very common if you have used scientific RPN calculators before. RPN Calculus has a build in constant values database. The database contains over 120 scientific constants of different categories like e.g. Mathematics, Physics or Astronomy. Since the constants database is user extendable, you can add constant values that you are may be missing in the default set of constants. RPN Calculus can print out your values on the stack and the memory.

About

ReadableCalc

Features
Read full description

ReadableCalc is a calculator app that displays large numbers—like 3 trillion 500 billion—in readable units. It’s designed to make extremely large numbers more intuitive at a glance. Main Features • Supports four basic operations (+, −, ×, ÷) • Displays results in English numeric units for easy readability • Handles decimals and negative numbers • DEL button for deleting one character at a time (Long press to clear the entire expression) • Long press on expressions or results to copy • Tap on the “readable” result to toggle display between: • Short scale / Long scale / Kanji numerals Additional features in landscape mode: • “00”, “000”, and “0000” buttons for quickly adding zeros • “x²” and “x³” buttons for quick exponentiation Note: • Numbers exceeding 200 digits may be rounded due to calculation and display limitations. Please be cautious if you need high precision. • Short scale and Long scale support numbers up to 10^198. • Kanji numeral display supports up to 10^72. Larger numbers are shown in Arabic numerals instead.

Screenshots

ReadableCalc3 screens

Verdict

The call

The clearest difference is price: ReadableCalc at Free against RPN Calculus's $1.99. ReadableCalc also leads on update cadence (weekly vs every 4 months) and device support (3 vs 1). On ads, in-app purchases and iOS requirement 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

ReadableCalc is free to download; RPN Calculus costs $1.99 up front. Neither carries in-app purchases, so what you see is what you pay.

UpkeepUpdate frequency

RPN Calculus ships an update every 4 months, ReadableCalc weekly. The most recent releases landed on September 28, 2026 and October 7, 2026 respectively.

Scorecard3 real differences · 7 level
RPN Calculus versus ReadableCalc: the parameters behind the verdict, then further details
ParameterRPN CalculusReadableCalc
Price$1.99Free — better
Rating4.0 (1 ratings) — better—
Positive reviews100.0% of reviews—
Number of ratings1 — better—
Update frequencyEvery 4 monthsWeekly — better
AdsNoNo
In-app purchasesNoNo
MonetizationPaid—
DevicesiPadiPhone, iPad, iPod — better
Requires iOS12.012.0
Further details — not scored
Size11 MB28 MB
Age rating4+4+
DeveloperThomas BraunYONAGARE LAB

In-app purchases

None

RPN Calculus

No in-app purchases

None

ReadableCalc

No in-app purchases

Questions

Is RPN Calculus free?
RPN Calculus costs $1.99, with no in-app purchases.
Is ReadableCalc free?
ReadableCalc is free to download, with no in-app purchases.
Do RPN Calculus or ReadableCalc have ads?
Neither RPN Calculus nor ReadableCalc shows ads.
Which is updated more often, RPN Calculus or ReadableCalc?
RPN Calculus ships an update every 4 months, and ReadableCalc weekly. Most recently, RPN Calculus was updated on September 28, 2026 and ReadableCalc on October 7, 2026.

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