Calca — The Math App That Understands Your Writing

I’ll never forget the first time I installed Mathematica in college. I was excited by the demos, and wanted to see how much it could help me take my calculus knowledge further — and take the drudgery out of math. Turns out, it was far more complicated to use than I ever anticipated, even more so than my trusty TI-89.

Couldn’t CAS — computer algebra systems — be a bit less complex and more accessible to everyone who doesn’t have time to take a whole class on using them? Computers were designed originally to solve complex math, but normal calculators, spreadsheets, and CAS systems have remained too basic on the one end and too complex on the other to change the way most of us feel about math.

It’s more than understandable that we’d tend to be skeptical when a new app claims to make math simpler for everything from engineering to basic budgets at the same time — but that’s exactly what Calca claims. It’s a markdown text editor fused with a CAS; can it possibly be the answer to the frustrations of math?

Calculated Writing

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Calca at first glance would seem to be a text editor more than a math tool, but dig deeper and it’s easily more of the latter than the former. But it’s not a half-bad text editor at that, complete with Markdown support that’ll show the formatting as you add it and makes links clickable.  Everything — including the calculated numbers — are saved in your Calca document in plain text format with a .txt extension, so you can open your notes and calculations in any app or share the finished document with anyone even if they’re not on a Mac.

But that’s not the best part. The best part is Calca’s brilliant math engine that lets you type out equations just as you’d solve them on paper, and then it’ll go ahead and solve them for you when you type the function name followed by =>. You can write everything out in words, as in the examples above, defining variables naturally, and then ask it what the final answer is. 99.9% of the time, it’ll give you back exactly what you’re looking for (and the other 0.1% of the time, you’ll realize that you’ve messed something up, declaring a variable twice or mistyping something).

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Calca is very easy to use. Essentially, you can declare a variable by using any normal word or phrase, followed by an = and the value or equation it’s equal to. This can be something simple, such as the things that are in your budget, or it can be a standard f(x)= algebra function. Then, you can see the final value of your variable by typing your variable followed by =>. Anything in bold black is a variable, anything blue is a number value, and anything with a grey background is a result that’s been generated by Calca.

Then, if you need more info, you can find out numerical facts from Google directly in the app. Just type in “USD to Euro exchange rate” or “distance from earth to sun” or anything else you want to find, then type =? and Calca will find the answer for you from Google. You can then use that in your following equations. It won’t find everything, but I’ve already found it powerful and useful.

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Calca goes far beyond the basic math you’d think of at first with an app like this, and can do everything from compute logs, solve matrices, compute basic logic statements and for statements, solve functions for a variable, or even just simplify equations as much as it can. Just look through the examples on the Calca site to see what it can do — it’s one powerful app.

Haven’t We Seen This Before?

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It’d be impossible to hear about Calca without thinking of Soulver, the original text-based simple calculator for the Mac. There’s a lot of similarities, but Calca is definitely the more powerful of the two. Soulver is designed to keep things simple, with calculation bar on the right that automatically shows the value of each line, and a sum at the bottom. You can use variables and solve simple functions with it, depending on how you set them up, but its primary purpose is more ordinary calculations such as budgets that end with a tally at the bottom.

Soulver is likely simpler to get started with, but it can be confusing in its own right, and I’d tend to think most people who’d like Soulver would equally like Calca. You may miss Soulver’s quick conversions, though, and if you’re looking for the simplest way to do quick text-based math that mainly involves sums and conversions, it still can come out on top. Calca’s Markdown text formatting, built-in Google search function, and far cheaper price tag, though, make it more attractive, even aside from the advanced math features.


Calca is an incredibly promising new way to work with math and text together on your Mac, one that’s even more surprising than FoldingText‘s text-based timer and other plain text innovations we’ve seen recently. It’s really, really impressive, and is an app you’ll have to try out if you use math often at all.

It’s already got a companion iPad app — one that actually came slightly before the Mac version — and iCloud sync, so it’s one of the best ways to calculate and keep your thoughts straight at the same time, anywhere you are.


A Markdown text editor and computer algebra system happily married together, Calca lets you compute naturally. A text editor for engineers, one that's still a math app for the rest of us.