A simple, powerful thinking tool.

Calculist is a plain text note-taking system for problem solving.



Write down your thoughts, ideas, and data in the form of lists.

Focus your attention by zooming in to a specific list, and zoom out to see the broader context.

Remove clutter by collapsing lists, and expand when needed.



Link thoughts together through references to form knowledge graphs.

Specify source-of-truth lists and embed values through lookups.

Use search mode to find and filter with ease.



Compute values and process data using expressions, functions, and variables.

Define reusable patterns for common structures and forms.

Create lexicons for semantically meaningful formatting.

Built for problem solving

Most note-taking apps prioritize capturing and organizing information into an external system. Information management is framed as the primary concern, and problem solving is secondary.

Calculist puts problem solving first. That means Calculist helps you focus on the important things rather than just manage information.

With Calculist, your notes serve you, not the other way around.

Space to think

Most note-taking apps require you to navigate an overwhelming number of features.

Calculist keeps it simple with a minimal, unobtrusive interface that gives your mind space to think, free of distraction. Features are there when you need them and stay hidden when you don't.

Peace of mind

Under the hood, Calculist is a human-readable markup language, and Calculist documents are ordinary, version-controlable, future-proof plain text files. No complicated backend data model or opaque metadata. Just simple, transparent plain text.

Calculist is also open-source under the MIT license, meaning your notes are never locked in to a proprietary system. Your notes are yours.