# Calca — Advanced symbolic calculator

> Advanced symbolic calculator and Markdown editor for instant equation solving and expression simplification. (iPhone/iPad app by Krueger Systems, Inc..)

- Source: https://appshunter.io/ios/app/calca/id635757879 (this page in markdown: same URL + `.md`)
- Developer: [Krueger Systems, Inc.](https://appshunter.io/developer/299293363)
- Category: Productivity, Education
- Price: $9.99 with in-app purchases
- Rating: 4.50/5 from 153 App Store ratings · 170 written reviews indexed
- Age rating: 4+
- Requires: iOS 15.0 · 78 MB
- Languages: American English
- Released: 2013-07-06
- Data updated: 2026-08-29
- Monetization: free with in-app purchases
- User reviews in markdown: https://appshunter.io/ios/app/calca/id635757879/reviews.md

## What is Calca?

Calca is a powerful symbolic calculator that gives you instant answers as you type. It solves equations and simplifies complex expressions - it's a computer algebra system in your pocket! It's also a rich Markdown text editor so that you can explain your ideas alongside your calculations. 

Calca is perfect for professionals and students - anyone who works with numbers and equations. Variables and functions can be created with only a few keystrokes and can be manipulated with a rich library of operators and functions. 

Calca updates as you type - just like a spreadsheet. You can declare variables, edit their values and watch everything update before your eyes. Since everything is calculated on the device - no network needed - you get answers instantaneously. 

All calculations are stored as plain text so you can easily share them with other editors and move them from device to device. Calca has been designed to work with iCloud documents so all your devices can access your calculations - you'll always have the latest files ready for viewing and editing. 

Calca comes with a suite of examples to help you get started covering topics from home mortgages to kinetics. All these examples are fully explained within Calca itself. 

Are you still using a desktop calculator? Are you using the calculator with the giant buttons that came with your OS? Computers are much more capable than doing simple one-line arithmetic - put your machine to work with Calca!

Calculation Features:

• Variables `x = 42`
• Functions `f(c) = 9/5*c + 32` and even recursive functions
• Units `42 mph in kmph` and currency `¥599 in $`
• Solves equations (`x + 2x + 4x = 42`, what is x?)
• Matrices with inverses so you can solve linear equations
• Sum, prod, map, and reduce operations on lists, matrices, and ranges
• Trigonometry and complex numbers
• Derivatives of functions
• Logic operations and if statements
• Binary math (& and |) and support for binary and hex number (`0xA9` and `0b1010`)
• Keeps track of units (m, s, m/s, m/s^2, etc.) so you can verify your equations as you compute

Please visit http://calca.io to see lots of examples. Thank you for looking!

## Key features

- Symbolic calculation
- Equation solving
- Expression simplification
- Markdown text editor
- Real-time updates
- Unit and currency conversion
- Matrix operations

## Pricing and in-app purchases

Base price: $9.99.

**One-time purchases**

| Purchase | Price | Type |
| --- | --- | --- |
| 12-Month Optional Patronage | $7.99 | one-time |
| 6-Month Optional Patronage | $4.99 | one-time |


## What do users think of Calca?

Overall sentiment: mixed

**Pros**

- 💡 Unique blend of text editor and calculator
- 📝 Markdown support for documentation
- 🔄 Dynamic recalculation of all values
- ⚙️ Powerful mathematical and algebraic capabilities
- 📊 Unit conversion and unit-aware calculations
- 💾 Plain text file format for portability
- 🔗 iCloud sync across devices
- 📈 Graphing and plotting functionality
- 🎯 Intuitive syntax and easy to learn
- 💰 One-time purchase model (historically)

**Cons**

- 🐛 Magic Keyboard input bugs on iPad
- ⚠️ Appears abandoned or poorly maintained
- 🐛 Text selection issues with external keyboards
- 📱 iPad landscape mode problems
- 🐛 Cursor jumping and screen jumping during editing
- 🚫 Limited file management options
- 🐛 Occasional crashes and stability issues
- ⏱️ Slow input responsiveness at times
- 🔢 Precision issues with large number calculations
- 🐛 Number editing gesture conflicts with normal text selection

**Commonly reported bugs**

- Magic Keyboard causes number input to overwrite instead of append
- Text selection before numbers triggers increment/decrement instead of selecting
- Cursor jumps forward and backward with external keyboards
- iPad Pro keyboard truncation in portrait mode
- Arrow key (=>) doesn't work in landscape mode
- App crashes on startup on some devices
- File saving is temperamental and causes data loss
- Folders don't persist unless calculations created within them
- Large number calculations lose precision (10^100 + 1 - 10^100 returns 0 instead of 1)
- Keyboard focus issues on iPad with Magic Keyboard
- iOS 13+ button adaptation issues
- Spinning beach ball on very large calculations

**Most requested features**

- Files app and document browser integration
- Dropbox and Google Drive support
- Date calculation functionality
- Looping and iteration support
- User-defined function storage in separate files
- Temperature unit support (Celsius, Fahrenheit)
- Logarithmic and non-proportional unit definitions
- Multiple parametric plots simultaneously
- Landscape mode optimization
- Tabular data and multi-row markdown table support
- Dark mode (now implemented)
- Subscription model option for ongoing development
- Decimal place formatting control
- Charting and financial functions
- Better document management interface

## Recent user reviews (10 of 170)

All indexed reviews: https://appshunter.io/ios/app/calca/id635757879/reviews.md

### 5/5 — My favorite app for thinking with numbers

*2025-11-04*

I’m not even a math person but I love this thing. Unlike a spreadsheet, the operations are in plain sight, so they are part of the story. And unlike Soulver (which is also great in its own way) I can interleave text such that I can describe a scenario, make a case, frame the numbers, etc.

### 5/5 — Best calculator app by a wide margin

*2025-09-19*

Calc is pretty much all the good things in one. It lets you enter equations, solves them algebraically, handles graphing, is super flexible and free-form to the point where you think, document, and calculate all at once.

### 5/5 — Love it!

*2025-08-26, version 1.6.1*

So useful. Use it all the time on iPhone and my MacBook.

### 1/5 — A cessé  de fonctionner

*2025-05-05*

Depuis une récente mise à jour, l'app ne fonctionne plus. Le développeur contacté n'a pas répondu. J'ai dû basculer sur une feuille de calcul dans Apple Numbers. Dommage, Calca était bien pratique.

### 5/5 — Fantastic app

*2025-03-11*

I’ve used Calca for years on iOS and Mac, and I love it for all sorts of computation. 

The most recent update with iOS 18 support fixes some issues I’ve hit with iPad Pro and Magic Keyboards—I really appreciate it!

### 4/5 — Not completely accurate

*2025-02-17, version 1.5.1*

I had hoped that, being based on a CAS, it would be able to handle cases like this:

(10^100) + 1 - (10^100) => 0

As you can see (this is pasted from Calca), it does not. The correct answer is 1.

### 5/5 — One of the best apps despite maybe being abandoned

*2024-09-10, version 1.5.1*

I first got Calca when it originally came out (and way before I did for real 🥲), over 10 years ago. I was in college and I had an iPhone 4s, I think. It had apps, most of them not very useful. 

Calca was *something else*. 

Calca could do math, and Calca made it convenient to do math that involved more than just punching in two numbers to get a single result. No longer did I need to break out a spreadsheet (which are still awkward on a phone, even in 2024, even on our now massive smartphone screens). I could calculate the rent split for my college roommates. I could calculate the total cost of a trip for me and my friends, with a bunch of flight tickets, accommodations, and whatever else, with the total cost split between all of us. I could estimate fuel costs given the fuel efficiency of a car. I could calculate means, standard deviations, and other arbitrary statistics on some data I was thinking about (don't you hate not having an app on your phone for figuring out stats for some random piece of data?). I could plot things. 

And I could annotate it all with Markdown, which I had then only just discovered. All on my phone. 

It was probably the first app I ever got on my phone that made it very real that this thing I always have on me is actually a legit computer, and having a computer that is always on me is actually useful. (Except for when it's the opposite of useful, but that's not Calca's fault).

Calca is not perfect. Over the years, I have encountered a fair amount of weird behavior, and anything really-really complex can still be awkward and error-prone. Calca's unit-aware calculations, while really cool, have also sometimes caused bizarre results. But when it has worked — and most of the time, it has — it has been magical. I only have weird behavior to complain about because I still come back to it and use it, a decade and who knows how many smartphone generations later. 

I wont deny that I'd appreciate it if the developer came back to this app to give it some love. But also... I get it. 11 years is a *long* time, and I only paid for Calca once (that was nice, by the way, to be able to pay for an app just once, and have it keep working for over a decade). 

Even if it's flawed, even if it's maybe abandoned, even if I now have a full-blown Python interpreter on my phone, with a whole host of numerical computation and data analysis libraries (imagine that, college me from 11 years ago), I still keep coming back to Calca. 

If I could give Calca 6 stars, or 11, or a usize::MAX, I would. If I could pay for it again, (and then maybe a third time), just to say "thank you," I would.  

It doesn't have to be perfect to be one of the best.

### 5/5 — Smartest app I know

*2024-02-27, version 1.5.1*

Everybody should know this exists, this is an incredibly useful app.

### 5/5 — Greates calc that I know

*2024-02-22, version 1.5.1*

Both on macOS and iOS a greatest calc app. 
(scrolling issues fixed long time ago)
Implementation of "notepad calc" is a best in class. I'm happy to find it!

### 5/5 — Excellent App

*2024-01-28*

This app is unique and there is nothing else quite like it.   I use it in place of Excel when multiple calculations are required along with extensive text.   
That said, it’s been several years since it’s been updated so I’m concerned the developer may have abandoned the project.   Calca is among my core apps so I’d be open to a subscription offering to compensate the developer and ensure it remains sustainable.

## Frequently asked questions about Calca

### What does Calca do?

Calca is a powerful symbolic calculator that solves equations and simplifies complex expressions. It also functions as a rich Markdown text editor, allowing you to explain your calculations alongside your work. It's designed to be a computer algebra system accessible on your mobile device.

### What are the key calculation features?

Key features include variable and function declaration, unit and currency conversion, equation solving, matrix operations with inverses, list and matrix operations, trigonometry, complex numbers, derivatives, logic operations, and binary math. It also tracks units to help verify equations.

### How much does Calca cost?

The application is available for free with in-app purchases. This model allows users to try out the core functionality before deciding to unlock additional features or capabilities through purchases.

### What devices is Calca compatible with?

Calca is designed to work across multiple devices, leveraging iCloud documents for seamless syncing. This means your calculations can be accessed and edited on any device where you use Calca, ensuring you always have the latest files available.

### Who would benefit from using Calca?

Calca is ideal for professionals and students who frequently work with numbers and equations. Its advanced calculation capabilities and integrated text editor make it useful for tasks ranging from complex mathematical analysis to explaining financial models or scientific concepts.

## Version history (last 5 releases)

### 1.7.2 — 2025-10-17

* New binary shift operators (like C's)
* More detailed reason if Apple Intelligence fails
* Fix toolbar colors when editing documents

### 1.7.1 — 2025-09-22

This version fixes links to document sections

Version 1.7 Changes:

* Apple Intelligence Integration: Calca now uses Apple Intelligence, leveraging on-device neural networks to answer =? queries. This means your data stays private and secure—no more sending queries to external services. Enjoy powerful, instant, and private calculations and data lookups, right on your device.

* Updated for iOS 26: The app is fully updated and optimized for iOS 26, ensuring the best experience on the latest devices.

* Performance and Stability: Numerous improvements and bug fixes for a smoother, more reliable experience.

### 1.7 — 2025-09-16

* Apple Intelligence Integration: Calca now uses Apple Intelligence, leveraging on-device neural networks to answer =? queries. This means your data stays private and secure—no more sending queries to external services. Enjoy powerful, instant, and private calculations and data lookups, right on your device.

* Updated for iOS 26: The app is fully updated and optimized for iOS 26, ensuring the best experience on the latest devices.

* Performance and Stability: Numerous improvements and bug fixes for a smoother, more reliable experience.

### 1.6.1 — 2025-03-11

Support for iOS 18

### 1.5.1 — 2020-09-18

* Updated for iOS 14 and iPadOS 14
* New `mean` and `average` functions for easy data summary
* Fix iPad keyboard thanks to Jon Edlund
* Fix unicode (non-English and Emoji) input thanks to Ivan Savochenko
* Fix dark mode highlighting
* Fix currency updates

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## More apps by Krueger Systems, Inc.

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All apps by Krueger Systems, Inc.: https://appshunter.io/developer/299293363

## Related topics

[calca app](https://appshunter.io/ios/topics/calca-app)

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*Data collected daily from the US App Store and indexed by [AppsHunter](https://appshunter.io/). User reviews are verbatim App Store reviews. Ratings, prices and chart positions refresh continuously; this snapshot is from 2026-08-29.*