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Best calculator apps in 2021

best calculator apps
(Image credit: Georgejmclittle/Shutterstock)

Who needs a pocket calculator when you've got one of the best calculator apps on your smartphone? After all, even an average phone can top the computational powers of a handheld calculator — and you only have to tote around one device instead of two.

Of course, most phones ship with their own built-own calculator apps. As good as those are, they lack the sophisticated features you'll find in the best calculator apps — particularly if you need to do a lot of scientific calculations.

If you need more power than what your phone already provides, give one of the best calculator apps a try.

The best calculator apps you can download right now

1. Pcalc Lite (iOS: Free, with in-app purchases)

best calculator apps Pcalc Lite

(Image credit: TLA Systems)

PCalc Lite for iOS has a well-deserved spot on the best calculator apps list as a free, extremely flexible scientific calculator armed with powerful features. While the basic app is outstanding on its own, you can also turn to valuable add-ons. 

The basic package gives you a fair amount to work with, such as trigonometric and logarithmic functions, a radian mode, undo and redo operations, as well as unit conversions and constants. Users looking for more power can buy additional features and operations through in-app purchases, or or spring for the premium version of PCalc for $9.99.

Download PCalc Lite: iOS

2. Calzy (iOS: $1.99)

best calculator apps Calzy

(Image credit: Wapple Stuff)

Calzy takes a neat approach to calculator apps with a "Memory Area" for quickly saving and labeling calculations, variables and other bits of data that you might want to store for easy reference across multiple sessions. The app also includes a configurable keyboard, 3D touch support, scientific functions, history and bookmarking, as well as multitasking support. 

Calzy an excellent all-around calculator app, so it's no surprise that this was a past winner of one of Apple's app design awards.

Download Calzy: iOS

3. Calcularium (iOS: Free)

best calculator apps Calcularium

(Image credit: InVooDoo)

InVooDoo’s Calcularium combines some neat controls with powerful tools for inputting and editing your calculations. The result is a calculator app that’s easy to use while also featuring some great functionality under the hood. 

Users can plug in the numbers with the traditional keyboard or input equations through voice or photo mode, and then label each number and variable for quick search and recall. Gesture controls let you rearrange elements of each equation, and you can save formulas and variables or break down individual variables into sub-equations. 

Calcularium does come with a lot of features, making the built-in video tutorials narrated by Siri a particularly useful function.

Download Calcularium: iOS

4. Numerical 2 (iOS: Free)

best calculator apps: Numerical

(Image credit: Andrew J. Clark)

Numerical2 is an app without equals, literally. The app speeds up input by doing away with the equals button, as well as automatically applying brackets to operations. 

It's not just about speed though. Numerical fields scientific calculator functions as well as fraction operations and special numbers such as Pi, E and infinity. The app supports landscape mode, split-screen multitasking, and even includes a custom keyboard for doing calculations within another app. 

On top of all that, Numerical also comes with multiple themes and a theme maker.

Download Numerical2: iOS

5. CalcNote (Android: Free)

best calculator apps calcnote

(Image credit: burton999 calculator developer)

Traditional desktop calculators are familiar but don’t infuse context into your calculations. Yet spreadsheets can be overkill for quick sums. CalcNote provides a middle ground, in combining a notepad with a calculator. This means you write out your sums in natural language, and the app extracts the important bits and tots up the numbers.

If you’ve used macOS (and previously iOS) app Soulver, the concept will be familiar. And although CalcNote isn’t as polished nor as powerful as Soulver, it’s a great way to keep track of expenses and to add up bills, not least given that you can quickly and easily reference previous line totals in subsequent lines. If you like the free version, there’s also an ad-free pro alternative ($5.49) to consider.

Download CalcNote: Android

6. HiPER (Android: Free)

best calculator app HiPER

(Image credit: HiPER Development Studio)

Rather than aim for the generic calculator experience, HiPER focuses like a laser beam on delivering an excellent scientific calculator app for Android smartphones and tablets. 

Mimicking the layout of traditional scientific calculators, HiPER includes both basic arithmetic operations as well as a dizzying arsenal of functions and special features, including fraction operations, mixed numbers and more, all with a built-in help feature to aid users in making sense of things. HiPER supports a variety of layout options optimized for phone screens and tablets. 

To get the most from the app, you’ll need to either enable ads or spring for the $3.49 Pro version, which unlocks expression mode, graphing, expanded precision (100 significant digits, 9 digits of exponents) and symbolic computation.

Download HiPER: Android

7. Scalar (Android: Free)

best calculator apps: Scalar

(Image credit: Scalar Math)

It seems almost a shame to just call Scalar a calculator, as this Android app does a ton more. Certainly, it’s a capable scientific calculator, with arguments, functions, user-defined functions, arguments and variables. But what makes Scalar shine is its script creation and editing tools for automating routine or advanced calculations, complete with syntax aides to help you organize your script writing.

Scalar is ad-supported, with a $2.49 pro version removing advertising and offering premium features like expanded script editing and saving options. While it would be overkill for splitting the restaurant tab, Scalar is a powerful and interesting app to explore for users doing more complex math.

Download Scalar: Android

8. Mobi Calculator (Android: Free)

Mobi Calculator

(Image credit: IP)

Mobi Calculator (formerly CubeCalculator) has been a long-time staple for Android users looking for a powerful and customizable calculator app. The main screen covers your basic arithmetic operations and parentheses, as well as two customizable buttons. A Mode button provides access to trigonometric and logarithmic functions. The app's settings menu provides hexadecimal, binary and octal support, as well as a viewable 50-line operation history. 

The $1.49 pro version allows for a 1,000-line history, support for five-line expressions, and additional visual themes.

Download Mobi Calculator: Android

9. Calculator ++ (Android: Free)

best calculator apps: calculator plus plus

(Image credit: Sergey Solovyev)

Calculator++ is another high quality, feature-packed Android calculator that comes loaded with tons of operations, variables, modes and settings sure to warm the heart of a dedicated cruncher. 

It's your scientific and graphing calculator all wrapped up into a single convenient, mobile package, with an equation editor, operation history, built-in and user definable variables, automatic expression simplification, complex calculations, a windowed mode and more. Calculator ++ is ad-supported, but only displays ads in its secondary screens.

Download Calculator++: Android

10. Desmos Graphing Calculator (Android, iOS: Free)

best calculator apps Desmos Graphing Calculator

(Image credit: Desmos)

Desmos Graphing Calculator is a free, powerful graphing calculator app that covers a wide variety of graphing functions and works fully offline without any problems. 

Users can input functions to display on a graph (with options for the Cartesian, polar, and parametric coordinate systems), using sliders to animate parameters, view output tables, input points, find the best fit line and more. This is a feature-packed graphing calculator that's perfect for the student on a budget.

Download Desmos Graphing Calculator: Android, iOS

11. Photomath (Android, iOS: Free)

best calculator apps: Photomath

(Image credit: Photomath)

Photomath turns a phone's camera into a calculator, with users able to use their camera viewfinder to scan and instantly solve math problems. 

Scan a problem, and the app displays the final answer along with a step-by-step breakdown of the problem's solution so that you can learn how to figure out solutions on your own. 

Photomath provides support for alternative answers, as well as a smart calculator for editing scanned equations and a new graphing mode. The app handles everything from basic algebra to linear, quadratic, and absolute equations and inequalities, systems of equations, trigonometry, and more with equal aplomb.

Download Photomath: Android, iOS

12. Wolfram Alpha (Android, iOS: $2.99)

best calculator apps Wolfram Alpha

(Image credit: Wolfram Alpha)

It may seem a disservice to the power of Wolfram Alpha to lump it in among calculator apps, but the app deserves a place here because Wolfram Alpha's computational knowledge engine is a wizard when it comes to queries involving math, numbers, calculations and statistics (along with 29 other disciplines). 

Not only will Wolfram Alpha help you do the math, it'll also give you formula details, graphic representations and explanations for how the app got to the solution. 

The major downside? Wolfram Alpha needs an internet connection, so if you've got spotty mobile signal, you're going to need another backup calculator.

Download Wolfram Alpha: Android, iOS

13. MyScript Calculator 2 (Android: Free; iOS: $2.99)

best calculator apps MyScript

(Image credit: MyScript)

MyScript Calculator 2 comes to the rescue of those of us accustomed to writing down equations on pen and paper rather than punching them into a calculator. A handwriting recognition system allows users to write down equations, with the app calculating the results. 

MyScript supports basic arithmetic, as well as percent, square roots, trigonometric (and inverse) functions, logarithms and constants such as pi and Euler's number. Version 2 adds extras like history, a memory function, multi-line support, dragging and dropping, and a ton of usability improvements.

Download MyScript Calculator 2: Android, iOS

14. CalcTape Calculator with Tape (Android: Free)

best calculator apps: CalcTape

(Image credit: Schoettler Software)

CalcTape Calculator is an excellent free app that draws inspiration from the traditional office tape calculator and improves on it. Users can enter a long string of figures and operations while being able to view their results in a scrolling tape, allowing you to keep track of a long calculation. 

You can go back and edit steps in the tape, with all operations down the line being automatically adjusted. Users can add text labels to individual steps in the tape, and the entire reel can be copied to a clipboard in order to be emailed or used in a word processor.

Download CalcTape Calculator: Android, iOS

15. Digits Tape Calculator (iOS: $1.99)

(Image credit: Shift)

Digits is a tape-style calculator for iOS devices that allows users to keep track of long calculations on a history reel, complete with text labels. Unlike a tape calculator, though, Digits allows users to go back in the calculation history and change operations or figures, with those changes automatically figured in down the line. 

The app particularly shines in its ability to print the tape reel or share it straight to email, VoiceOver accessibility support, and split view compatibility on the iPad, making for a handy office companion. 

Updates over the years have added the ability to re-order entries and operations, and interface options like a Night mode in the Pro Design in-app purchase; another in-app purchase adds extended exporting options.

Download Digits Tape Calculator: iOS