Comparison

Calculator ∞ vs Scientific Calculator Plus 991

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

Head to head
About

Calculator ∞

This advanced calculator app offers a powerful math core and algebra engine for basic to complex calculations. It includes features like step-by-step solutions, handwriting recognition, and 2D graphing, making it suitable for students, engineers, and programmers.

Highlights
  • Step-by-step solution hints
  • Math Photos Solver
  • Handwriting Recognition
  • AI Math Problem Solver
  • 2D Graphing
  • Unit Converter
  • Matrix/Vector Mode
Features
Currently charting
Read full description

◉ Top Paid Educational Apps in US, UK, AUS, GER,... ◉ QAppReview.com Rated 9/10 ◉ Users Reviewed: "Top Class Calculator !" The BEST Alternative to Graphing TI-83, TI-84, TI-89, Casio FX, Sharp EL,... Calculator Infinity (∞) – The sleek, multi-function calculator for iPhone/iPad is proud to offer a variety of features to satisfy all ranges of customers: The App possesses a powerful math core and algebra engine with mathematical display support, making it a viable tool for everyone from those looking for basic calculation to more advanced users, such as scientific computation, programmers, engineers, and math students. Calculator ∞ makes available everything you need – including a user manual and tutorial video clips – so you can master the app in a matter of minutes! ◉ Official Website: http://iPhoneCalculator.com ◉ ADVANCED FEATURES: ▸ Step-by-step solution (Hints) ▸ Math Photos Solver * ▸ Handwriting Recognition * ▸ Math Problem Solver (AI) * ▸ Well Organized of Functions ◉ GENERAL FEATURES: ▸ Universal Calculator App ¹ ▸ Support Multitasking (iPad) ▸ Support Wireless KB² ▸ Mathematical Display ▸ Edit & Export Expression/Result ▸ History Tape View ▸ Basic Calculations (+, -, x, ÷, %, Abs,...) ▸ Advanced Functions (Sin, Cos, Ln, X!, ^, √,…) ▸ Memory Variables (Including X,Y,Z,M) ▸ F(x) Customize Functions (F1, F2, F3) ▸ Unit Converter (40 Categories, 1000+ Units) ▸ Over 40 Common Constants ▸ Fraction and Degree/Angle Calculation ▸ Numeric Integral & Derivative Calculation ▸ Dual Skins (Silver Light & Carbon+) ▸ No Ads ◉ ALGEBRA FEATURES: ▸ Big Integer & Rational Number (Up to 500!) ▸ Expand and Factor Polynomials ▸ Indefinite integral & Derivative ▸ Two-side Limit ▸ Taylor Series Expansion ▸ Hints and Solutions ◉ 2D GRAPH: ▸ Simultaneous Graph ▸ Smooth Zoom & Transformation ▸ Support F(X,Y) = 0. E.g. Sin(X) + Cos(Y) = 0. ▸ Conic Equations (Parabola, Hyperbola, Ellipse) ▸ Get Intersections, Min, Max & Special Points ◉ CLOUD COMPUTING: ▸ Advanced Two-side Limit ▸ Advanced Indefinite Integral ▸ General Equations (Accurate Roots) ◉ EQUATIONS SOLVERS: ▸ General Equations (Numerical Roots) ▸ Quadratic & Cubic Equations ▸ System of Linear Equations (2 & 3 Unknowns) ◉ REGRESSION & STATISTICS: ▸ Modify & Sort Data ▸ Single Variable Statistics ▸ Linear, Quadratic, Power Regression ▸ Logarithmic & Exponential Regression ◉ COMPLEX CALCULATION: ▸ Polar & Rectangular Notation ▸ Argument, Conjugate Function ▸ Trigonometry Functions ▸ Logarithmic & Exponential Functions ◉ MATRIX/VECTOR MODE: ▸ Support Up to 7x7 Matrix ▸ Support Complex Numbers ▸ Cross, Dot Product ▸ Det, Inverse, Transpose ▸ Cramer’s Rule Solver ▸ Numerical Real Eigenvalues ◉ NUMBER BASE-N MODE: ▸ 15 Different Bases ▸ Support Up to 32 Bits Integer ▸ Binary Operation (NOT, OR, XOR, 2’S, …) ◉ MULTIPLE LANGUAGES: ▸ English, Spanish, German, ▸ French, Japanese, Chinese (*) In-App-Purchase is required ¹: Include iPhone SE, PRO, PRO-MAX, iPad... ²: Standard English KB Calculator ∞ is not only the Calculator IT IS THE MUST HAVE CALCULATOR !!! We love your feedback, Thanks a lot ! Please contact us for questions, bugs/crash reports, conversion requirements, etc.... Terms of Service: https://iphonecalculator.com/terms-of-service/

About

Scientific Calculator Plus 991

This app is a powerful scientific calculator with graphing capabilities, a formula library, and a unit converter. It offers natural display input, advanced math functions for algebra, calculus, and statistics, and supports various number bases and formats.

Highlights
  • Natural display input
  • Graphing module
  • Formula library
  • Unit and currency converter
  • Algebra and calculus tools
  • Matrix and vector operations
  • Statistical calculations
Features
Read full description

NCalc — Powerful Scientific Calculator, Graphing, and Converter NCalc combines a natural-display scientific calculator, advanced math tools, a full graphing module (as 83/84 calculator), a large formula library, and a comprehensive unit and currency converter—designed for students, engineers, and anyone who loves math. ◉ Main Calculator Features - Natural display: Enter expressions exactly as in textbooks—fractions, roots, exponents, and more—see results as written on paper. - Keyboard layout: Matches popular models for familiarity and speed: 115 ES Plus, 991 ES Plus, 300 ES Plus, and 991 EX. - Symbolic and numeric modes: Perform exact fraction calculation or evaluate numerically when needed. - Arbitrary precision integers: Work with very large integers without losing accuracy. - Output types: Choose from fraction, mixed fraction, decimal, repeating decimal, degrees/minutes/seconds, and polar coordinates. - Angle units: Degree, radian, and gradian (grade). - Decimal formatter: Display numbers in normal, engineering, engineering SI, scientific, or fixed formats. - Calculation history: Review and reuse past calculations with ease. - Copy and paste support for fast data entry and sharing. ◉ Algebra, Calculus, and Core Math - Algebra calculation: Expansion, factorization, simplification, and more. - Calculus calculator: Derivatives, integrals, and limits of expressions. - Complex number calculation: Arithmetic, polar/rectangular conversion, exponential, logarithm, powers, roots, and full trigonometric functions. ◉ Equations and Inequalities - Equation solver: Solve general equations, plus dedicated solvers for quadratic, cubic, and quartic equations. - System of equations solver: Solve systems with 2, 3, or 4 variables. - Inequality solvers: Quadratic, cubic, and quartic inequalities with interval-based solutions. ◉ Matrices and Vectors - Operations: Addition, subtraction, multiplication for matrices and vectors. - Advanced tools: Determinant, inverse, transpose, rank, eigenvalues, and eigenvectors. ◉ Statistics and Distributions - Statistical calculation: Descriptive stats and regression calculation (including a regression plotter). - Distribution calculation: Normal distribution, binomial distribution, Poisson distribution, t-distribution, chi-square distribution, and F-distribution. ◉ Number Bases and Formats - Base N calculation: Effortlessly switch between binary, octal, decimal, and hexadecimal, with arithmetic in each base. ◉ Tables, Variables, and Custom Functions - Table Generator: Generate value tables based on any expression and range. - Calculator variables: Store values and reuse them across calculations. - User-defined functions: Create your own functions to streamline repetitive work. - Built-in constants: A rich set of mathematical and physical constants. ◉ Formulas - Extensive formula collection: Math and Physics formulas, clearly categorized—ideal for secondary school, high school, and university students. ◉ Unit Converter - Currency Converter - 1000+ unit conversions ◉ Graphing as 83, 84 calculator - Cartesian functions, implicit plots, polar, and parametric. - Tracing, roots, intersections, extrema, derivative, and integral evaluations on graphs. ◉ Auto-renewing subscription You may purchase an auto-renewing subscription through an In-App Purchase. • Auto-renewable subscription • Your subscription will be charged to your AppStore account at confirmation of purchase and will automatically renew (at the duration selected) unless auto-renew is turned off at least 24 hours before the end of the current period. • Current subscription may not be cancelled during the active subscription period; however, you can manage your subscription and/or turn off auto-renewal by visiting your AppStore Account Settings after purchase • Privacy policy and terms of use: https://ncalc-app.web.app/terms-of-services.html

Screenshots

Calculator ∞4 screens
Scientific Calculator Plus 9914 screens

Verdict

The call

The clearest difference is price: Scientific Calculator Plus 991 at Free against Calculator ∞'s $5.99. Scientific Calculator Plus 991 also leads on update cadence (fortnightly vs every 2 months) and review sentiment (92% vs 75%). Calculator ∞'s advantage is ads (none vs shown) and chart position (#109 vs unranked). On rating, ratings volume, 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

Scientific Calculator Plus 991 is free to download; Calculator ∞ costs $5.99 up front. Calculator ∞ sells 4 in-app purchases, starting at $3.49 per month and Scientific Calculator Plus 991 sells 4 in-app purchases, starting at $1.99 per month. Whichever you choose, the download price is not the number that matters.

ReceptionRating · Positive reviews · Number of ratings

On the App Store both sit at effectively the same score — 4.7 for Calculator ∞ against 4.7 for Scientific Calculator Plus 991. Both are backed by a comparable volume of ratings — 6.4K and 13K respectively. Written reviews are what separate them: 75% of Calculator ∞'s written reviews are positive against 92% of Scientific Calculator Plus 991's.

UpkeepUpdate frequency

Calculator ∞ ships an update every 2 months, Scientific Calculator Plus 991 fortnightly. Both last shipped on November 6, 2026.

Scorecard6 real differences · 5 level
Calculator ∞ versus Scientific Calculator Plus 991: the parameters behind the verdict, then further details
ParameterCalculator ∞Scientific Calculator Plus 991
Price$5.99Free — better
Rating4.7 (6.4K ratings) — better4.7 (13K ratings)
Positive reviews74.8% of reviews91.7% of reviews — better
Number of ratings6.4K13K — better
Update frequencyEvery 2 monthsFortnightly — better
AdsNo — betterYes
In-app purchasesYesYes
MonetizationFree with in-app purchasesFree with in-app purchases
Best chart rank#109 — better—
DevicesiPhone, iPad, iPodiPhone, iPad, iPod, Mac — better
Requires iOS12.1 — better15
Further details — not scored
Size46 MB169 MB
Age rating4+12+
DeveloperIncpt.MobisTran Duy

Customer experience

Calculator ∞

All ratings6,306 ratings
Positive93.6%
Neutral1.8%
Negative4.6%
Written reviews421 reviews
Positive74.8%
Neutral5.2%
Negative20.0%

Scientific Calculator Plus 991

All ratings12,520 ratings
Positive92.0%
Neutral2.6%
Negative5.4%
Written reviews509 reviews
Positive91.7%
Neutral3.1%
Negative5.1%

Bugs and requests

Calculator ∞

Not enough reviews yet to summarise bugs or requests.

Scientific Calculator Plus 991

Reported bugs

3 issues
  • Keyboard input stops working after switching screens
  • Incorrect calculation results for certain operations
  • App crashes on some devices after recent update

Requested features

5 requests
  • Add option to change display font and color
  • Improve cursor control and editing capabilities
  • Implement auto-simplification for complex expressions
  • Add more handwriting font options
  • Expand graphing and equation solving features

In-app purchases

4 purchases

Calculator ∞

Subscriptions2
  • Unlimited OCR/Writing 1 Month$3.491 Month
  • Unlimited OCR/Writing 3 Months$8.993 Months
One-time2
  • 400 AI Recognition & Queries$0.99
  • 900 AI Recognition & Queries$1.99
4 purchases

Scientific Calculator Plus 991

Subscriptions2
  • Calculator month subscription$1.991 Month
  • Calculator yearly subscription$3.991 Year
One-time2
  • Calculator Premium$5.99
  • Calculator Pro$5.99

Questions

Is Calculator ∞ free?
Calculator ∞ costs $5.99, and also offers in-app purchases.
Is Scientific Calculator Plus 991 free?
Scientific Calculator Plus 991 is free to download, with in-app purchases available.
Which has better reviews, Calculator ∞ or Scientific Calculator Plus 991?
Calculator ∞ is rated higher. Calculator ∞ averages 4.7 out of 5 from 6.4K ratings, while Scientific Calculator Plus 991 averages 4.7 from 13K ratings.
Do Calculator ∞ or Scientific Calculator Plus 991 have ads?
Scientific Calculator Plus 991 shows ads; Calculator ∞ does not.
Which is updated more often, Calculator ∞ or Scientific Calculator Plus 991?
Calculator ∞ ships an update every 2 months, and Scientific Calculator Plus 991 fortnightly. Most recently, Calculator ∞ was updated on November 6, 2026 and Scientific Calculator Plus 991 on November 6, 2026.

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