CalX

CalX is a natural-language calculator for macOS. Type your math the way you'd describe it - units, currencies, dates, even timezones - and the answer appears live in the column on the right.

Think of it as a scratch pad that does arithmetic. Each line evaluates as you type, results stay synced, and you can reference earlier lines without leaving the keyboard.

Highlights

1. Natural-language math - write expressions in plain English: 20 inches in cm, sqrt(2), 5% of 240. No equals sign, no special syntax.
2. Live currency & crypto - exchange rates refresh every hour from open.er-api and CoinGecko. $100 in EUR or 1 BTC just work.
3. Dates & timezones - today + 2 weeks, 10am NYC in Tokyo, now in London. 80+ cities and the usual short codes (PST/JST/CET/…).
4. Cross-line references - type sum, avg, or prev on its own line to pull values from the block above. Mixed units are filtered automatically.
5. Compound units - natural shorthand like 5 ft 9 in to cm or 1 hour 30 minutes works without a plus sign.
6. Click to copy - tap any result on the right and it lands in your clipboard with a soft toast confirmation.
7. Pin on top & global shortcut - keep CalX floating above other windows, and bring it to front from anywhere with a customizable hotkey (default ⌘⇧F).
8. Light & dark theme - compact macOS-native window with a soft mint accent in light mode and bright cyan in dark.
9. Persistent notes - your document stays exactly where you left it between sessions, no save button required.

How to use it

Open CalX, start typing in the big editor on the left. Each line is its own expression - comments start with # and a blank line resets the running block. Here are the patterns that cover most of what you'll want to do:

1. Plain math - 1 + 2 * 3, sqrt(2), sin(pi / 4), 2^10. Order of operations works the way you'd expect.
2. Convert units - 20 inches in cm, 5 ft 9 in to cm, 1 hour 30 minutes in seconds, 500 GB in TB.
3. Money & crypto - $9 in EUR, 1000000 VND in JPY, 1 BTC, 10 ETH in USD. Live rates handle the conversion.
4. Dates - today, today + 2 weeks, today - 30 days. Date arithmetic uses your computer's clock.
5. Timezones - 10am NYC in Tokyo, 3:30pm PST in CET, now in London. Multi-word cities are written together (NewYork, HongKong) or use abbreviations (NYC, HK).
6. Sum a column - list values on consecutive lines, then drop sum on the next line: it adds whatever's compatible above. avg gives the mean, total is an alias for sum.
7. Reference the previous result - prev * 2, prev + 10%. Comments don't break the chain.
8. Group with comments - start any line with # to label it. # Rent, # Groceries. Use a blank line to start a fresh totals block.
9. Copy a result - click any number in the right column. It copies to your clipboard with a tiny toast at the bottom.
10. Pin or summon - the pin icon in the title bar keeps the window on top of everything else. Press your global shortcut (default ⌘⇧F) from any app to bring CalX to focus.

Perfect for

1. Freelancers & remote workers - invoices in two currencies, hourly rates across timezones, quick budget math without opening a spreadsheet.
2. Travellers & expats - what's $50 in local money, what time is my call in Tokyo, how many hours is the flight.
3. Developers & designers - convert bytes, scratch-pad math during code review, sanity-check API price calculations against live rates.
4. Students - homework that mixes units (physics, chemistry), date intervals, percentage problems.
5. Anyone who keeps a calculator app open - pin CalX to the top corner, summon it with one key, and skip the dock dance.