How to use CalNote: a guide to the notepad calculator

Most calculators force you to think in buttons. You punch in a number, hit an operator, punch in another number, and hope you remember what you were calculating three steps ago.

CalNote works differently. You type math the way you think about it — as text, with names for things, organized across separate boards. It runs entirely in your browser, needs no account, and works offline.

This guide covers everything CalNote can do.

The basics: type and see results

Open app.calnote.eu and start typing. Each line is its own expression. Results appear instantly on the right:

10 + 5                     15
120 / 4                    30
2 ** 8                     256
(3 + 7) * 2               20

Standard operators work as you’d expect: + - * / for arithmetic, ** for exponents, % for remainder, and parentheses for grouping.

Variables: name your numbers

This is where CalNote pulls ahead of any basic calculator. Assign a value to a name with =, then reference it in any line below:

rent = 1200
utilities = 180
groceries = 400

rent + utilities + groceries    1780

Change rent to 1300 and every line that references it updates immediately. No re-entering numbers, no mental tracking.

Variables autocomplete as you type — start writing a name and press Tab to accept the suggestion. You can also double-click a variable name to rename it across the entire board.

Percentages that actually make sense

CalNote handles percentages contextually, the way people actually use them:

100 + 21%                  121
200 - 15%                  170
50 * 30%                   15

When you write 100 + 21%, CalNote understands you mean “add 21% of 100 to 100” — not “add 0.21.” That matches how you think about tax, tips, and discounts in the real world.

Currency conversion

CalNote supports 24 currencies. Use the symbol prefix or the currency code:

$100                       $100.00
€50                        €50.00
100 USD                    $100.00

$100 to €                  €88.00
€200 + $50 to £            £213.23

Supported currencies include USD, EUR, GBP, JPY, CHF, CAD, AUD, SEK, NOK, PLN, CZK, HUF, RON, TRY, CNY, KRW, INR, BRL, and more. Currency codes are case-insensitive, so 100 usd works the same as 100 USD.

Comments: annotate your math

Use // or # to add notes that don’t get evaluated. This is what makes CalNote a notepad calculator — you can explain your reasoning inline:

// Monthly budget
salary = 4200
tax = salary * 22%          924

# What's left after tax
net = salary - tax           3276

rent = 1100
net - rent                   2176  // after housing

Boards: organize by context

One board for your monthly budget. Another for a trip you’re planning. Another for splitting dinner last night. Boards keep separate calculations from bleeding into each other.

• Create a board — click the + tab or press Ctrl+N (Mac) / Alt+N (Windows)
• Switch boards — click tabs, press Cmd+Shift+< / Cmd+Shift+> to cycle, or Cmd+J to pick from a list
• Rename — double-click the tab name
• Close — middle-click the tab, press Ctrl+W / Alt+W, or click the X

Each board has its own variable scope. A variable defined in “Budget” won’t collide with one in “Travel.”

Search across everything

Press Cmd+K (or Ctrl+K) to open the search modal. It searches across all board names and all content — every line of every board. Results show which board and line number a match comes from, so you can jump straight there.

Keyboard shortcuts

CalNote is built for people who prefer the keyboard. Here’s the full list:

Navigation

• Cmd+K — Search boards and content
• Cmd+J — Board picker
• Cmd+Shift+< / Cmd+Shift+> — Previous / next tab
• Cmd+/ — Help & keyboard shortcuts

Boards

• Ctrl+N — New board
• Ctrl+W — Close current board

Editor

• Alt+↑ / Alt+↓ — Move line up / down
• Tab — Accept autocomplete
• Esc — Dismiss popups

Syntax highlighting

Everything is color-coded: variable names, numbers, operators, currency symbols, comments, and even URLs. If you accidentally redefine a variable, CalNote highlights the reassignment so you catch it immediately.

URLs in your notes are clickable — hold Cmd (or Ctrl) and click to open them.

Private by default

CalNote stores everything in your browser’s local storage. There’s no account to create, no data sent to a server, and no cloud sync. Your calculations stay on your device. The app works fully offline once loaded.

Why not just use a spreadsheet?

Spreadsheets are powerful, but they’re overkill for everyday math. You don’t need rows and columns to figure out how much you’re spending on rent, or to split a bill, or to convert currencies while traveling.

CalNote sits in the sweet spot between a basic calculator and a spreadsheet: structured enough to name things and organize work, simple enough that you’re calculating within seconds of opening it. No formulas to remember, no cell references, no menus. Just text in, answers out.

Ready to try it? Open app.calnote.eu — no sign-up, no download, free forever.