Calculations inside your notes

Write the question in plain words in any note, and Coffee shows the answer beside the line. The answer never enters your file, so your Markdown stays clean.

Coffee is a Markdown editor for the Mac, on macOS 15 or later. Calculations come with every plan, and with the 14 free days.

What you can write

20% of 50
price = $8 times 5
5 km in miles
100 C in F
$30 in BTC
Tokyo time
2:30 pm HKT in Berlin
today + 2 weeks
sqrt 16
255 in hex
20 is what % of 200
half of 175
37 to nearest 10
average of 36, 42 and 19
3 days ago
workdays until 24 Dec
3h 5m + 45 min
€40/hour * 7.5 hours

You can also name values and use them later. Try it on the home page, which runs the calculator in your browser.

Totals over a list

Write Total, sum, average, count, median, min or max under a block, and it works over the lines above. A bare amount or Label: amount counts. Rent 400 without the colon doesn't, as it can't be told from Chapter 2.

Select some numbers, even a column of a table, and Coffee shows their sum. Hold ⌥ and drag a number to try other values and watch the answers change.

What gets no answer

A line is either understood completely or left alone, so an ordinary sentence with a number in it stays quiet. So do dates like 05/11/2026, ranges like 2-3 days and phone numbers. Headings and table rows are skipped.

Your text stays yours

Results are drawn beside the line and aren't saved in the .md file, so other editors see only what you wrote. You can turn calculations off in Settings.

Clicking an answer copies it. PDF, Word, EPUB, HTML and Print include answers as the note shows them when you export, so 3 days ago becomes that day's date. Markdown and plain text exports don't include them.

Exchange rates

Rates are fetched only when a note converts a currency, and again when they're over an hour old. The request says nothing about your note. Offline, Coffee uses the last rates it saved, and shows their age once they're a day old. Units and time zones don't need a connection.

Questions

Are the answers saved in my Markdown file?

No. They appear beside the line and never enter the file.

Can Coffee convert currencies and crypto?

Yes, for example $30 in EUR or $30 in BTC. Rates are fetched only when a note needs them.

Does it handle time zones and dates?

Yes, for example Tokyo time, 2:30 pm HKT in Berlin or today + 2 weeks.

Does it work without a connection?

Sums, units, dates and time zones do. Currency lines use the last rates Coffee saved, and show no answer if it has never fetched any.