CalculonA notepad that calculates as you type
Calculon is a natural-language notepad calculator. Write lines with money, units and dates, and the answers show up on the right. It runs on Linux, Windows and macOS, in English and Ukrainian.
It's free and open source, under the MIT licence.
Examples
Every line is plain text. Calculon finds the numbers, money, units and dates in it and keeps the answers in a column on the right.
Currency answers here use the rates from , the snapshot that ships with the app. The app updates them once a day.
Features
Two themes
Ember, warm greys with orange, and Glacier, the slate blue on this page. Each comes in dark and light, or follows your system.
Sheets are plain files
Every sheet is a .txt file in a folder you pick. Sync it, back it up or grep it with any tool.
Rates that work offline
Calculon downloads exchange rates once a day and keeps the last ones, so currencies work without a network.
English and Ukrainian
Write sheets in either language, or both at once. Numbers follow the interface language: 1,234.56 or 1 234,56.
Spell check
It checks English and Ukrainian with the dictionaries already on your system, and skips numbers, units and variable names.
Help inside
The Help sheet (F1) shows every feature with live examples you can change. Keyboard Shortcuts in the Help menu lists the keys.
Questions
Is it free?
Yes. Calculon is open source under the MIT licence, and the code is on GitHub.
Does it work with Soulver sheets?
Mostly. Calculon follows the syntax of Soulver,
the notepad calculator for Mac and iPhone, for maths, money, units and dates, so
most sheets work in both. Timelines are different. Soulver marks their start and
end in its interface, and Calculon uses @from and @to
lines, which Soulver doesn't read. Calculon isn't made by Soulver's authors.
Does it work offline? What does it send?
Everything runs on your computer. The only thing Calculon downloads is exchange rates, once a day, from open.er-api.com or Frankfurter. Without a network it uses the last rates it has. There's no account and no tracking.
Where are my sheets?
In ~/Documents/Calculon, as plain .txt files, one per
sheet. Folders are real folders. You can pick another folder in Settings and sync
it with any tool.
How do I turn on spell check?
Calculon uses the Hunspell library and the dictionaries on your system. On Debian and Ubuntu:
sudo apt install libhunspell-1.7-0 hunspell-en-us hunspell-uk
On macOS, install Hunspell with Homebrew and put the en_US and uk_UA dictionaries
in ~/Library/Spelling. The
README has the
steps. Windows isn't supported yet.
Then turn it on with Check Spelling in the View menu, or press F7.