Everything a back-of-napkin calc should be
One window. Type on the left, answers on the right.
Live answers
Every line evaluates as you type. Mix notes and math freely — plain text just stays as notes.
Syntax highlighting
Numbers, units, keywords and functions are colour-coded, and every variable gets its own colour.
Variables
rent = 1200, then use rent anywhere below. Reference sum, average and prev too.
Plain-language percent
15% of 80, 50 + 18%, 20% off 50, 50 is what % of 200.
Units
Length, mass, time, volume, data, temperature, area and speed — 100 km/h in mph, 1 GB in MB.
Live currency
Real exchange rates plus crypto — $50 in EUR, 0.1 btc in usd. Cached for offline.
Dates & time zones
today + 30 days, today to christmas, 3pm New York to London.
Functions
sqrt, min/max, average, plus finance: compound(), mortgage().
Library & folders
Keep many calculations, organise them in folders, and a 30-day Trash for anything you delete. Autosaves.
Export
Send any calculation to CSV, Markdown, HTML or PDF with one shortcut (⌘E).
Local-first
Your calculations live on your Mac. No sign-up, no account, nothing to leak.
Mac-native
Built in SwiftUI. Fast, lightweight, and at home on macOS.