Basics
Type a calculation on any line and its result appears right beside it as a dimmed hint. Errors show inline in red. The total at the bottom sums all numeric results, and results are formatted with thousands separators.
returns 2
returns 7
returns 4
returns 4
returns 1
returns 1,000,000
| Operator | Function |
|---|---|
+ | Add |
- | Subtract |
* | Multiply |
/ | Divide |
^ | Power |
% | Remainder |
Many more functions and operators are available — see the mathjs documentation.
Tabs
Use the tabs at the top to keep separate worksheets. Every tab is saved automatically as you type.
- Switch — click a tab (or use
←/→once focused, orCtrl+Tab). - Reorder — click and drag a tab to a new position.
- Rename — double-click the tab name.
- Close — click the
×(you'll be asked to confirm). - Add — click the
+tab. - Export / Import — use the buttons in the Settings modal to download the active sheet as text or load one from a file.
- Share — the Share button copies a link that carries the active sheet inside it. Anyone who opens it is asked whether to open the sheet in a new tab; it never replaces what they already have. Nothing is uploaded: the sheet travels in the link's
#fragment, which browsers never send to a server.
Variables
Assign a value with = and reuse it on later lines. Use prev for the previous line's result, and sum/total/average/avg to aggregate the lines above until a blank line.
last line returns 15
last line returns 80
last line returns 30
last line returns 6
Functions
Store a function with f(x) = … and call it later. Numi-style aliases are available too: ln, fact, arcsin, arccos, arctan, root.
stores a function
returns 42
returns 120
returns 1
returns 2
Lists
Write a list with square brackets. Lists are 1-indexed: n[1] is the first
element. Slice with a range, assign elements, do element-wise arithmetic, and combine lists with
the mathjs functions.
[1, 2, 3]
10 (first element)
[20, 30, 40]
sets the second element
[4, 6]
returns 10
returns 5.5
[1, 2, 3]
[1, 2, 3, 4]
3
Sequences & iteration
A range start:end (with an optional :step) makes a list of numbers, and
calling a function with a range applies it to every element. Lists can be named and indexed like
any other variable.
[1, 2, 3, 4, 5]
[1, 3, 5, 7, 9]
3
[2, 4, 6, 8, 10]
returns 5050
returns 3
Percentages
Use of, on and off with % for percentage math.
returns 2
returns 31.5
returns 37.6
returns 50
returns 120
Operators & scales
Word operators and number scales work naturally.
returns 72
returns 5
returns 7
returns 42
returns 2,000
returns 2,000,000
Unit conversion
Convert units with to or in. CSS units are supported too: px, em and point.
returns 0.01 m
returns 7200 s
returns 5000 m
returns 86 degF
returns ≈ 37.8 px
returns 32 px
| Base | Unit |
|---|---|
| Length | meter (m), inch (in), foot (ft), yard (yd), mile (mi), link (li), rod (rd), chain (ch), angstrom, mil |
| Surface area |
m2, sqin, sqft, sqyd, sqmi, sqrd, sqch, sqmil, acre, hectare |
| Volume | m3, litre (l, L, lt, liter), cc, cuin, cuft, cuyd, teaspoon, tablespoon |
| Liquid volume |
minim (min), fluiddram (fldr), fluidounce (floz), gill (gi), cup (cp), pint (pt), quart (qt), gallon (gal), beerbarrel (bbl), oilbarrel (obl), hogshead, drop (gtt) |
| Angles | rad (radian), deg (degree), grad (gradian), cycle, arcsec (arcsecond), arcmin (arcminute) |
| Time | second (s, secs, seconds), minute (mins, minutes), hour (h, hr, hrs, hours), day (days), week (weeks), month (months), year (years), decade (decades), century (centuries), millennium (millennia) |
| Frequency | hertz (Hz) |
| Mass | gram(g), tonne, ton, grain (gr), dram (dr), ounce (oz), poundmass (lbm, lb, lbs), hundredweight (cwt), stick, stone |
| Electric current |
ampere (A) |
| Temperature | kelvin (K), celsius (degC), fahrenheit (degF), rankine (degR) |
| Amount of substance |
mole (mol) |
| Luminous intensity |
candela (cd) |
| Force | newton (N), dyne (dyn), poundforce (lbf), kip |
| Energy | joule (J), erg, Wh, BTU, electronvolt (eV) |
| Power | watt (W), hp |
| Pressure | Pa, psi, atm, torr, bar, mmHg, mmH2O, cmH2O |
| Electricity and magnetism |
ampere (A), coulomb (C), watt (W), volt (V), ohm, farad (F), weber (Wb), tesla (T), henry (H), siemens (S), electronvolt (eV) |
| Binary | bits (b), bytes (B) |
See the mathjs units reference for the full list.
Currency conversion
Convert between currencies using 3-letter ISO codes or symbols. Rates come from the European Central Bank (via frankfurter.dev) and are cached locally for offline use.
converts USD to EUR
converts to GBP
converts to EUR
converts to BRL
Supported codes: BRL, CAD, CHF, CNY, CZK, DKK, EUR, GBP, HKD, HUF, IDR, ILS, INR, ISK, JPY, KRW, MXN, MYR, NOK, NZD, PHP, PLN, RON, SEK, SGD, THB, TRY, USD, ZAR.
Dates
Convert unix timestamps with fromunix, get the current time with unix(), and use date units directly.
Jan 1, 1970…
Nov 3, 2015…
current timestamp
30.4375 days
Shortcuts & files
The active sheet can be exported and imported from the Settings modal or with the shortcuts below.
| Shortcut | Action |
|---|---|
⌘Z | Undo the last change in the tab |
⇧⌘Z | Redo |
Ctrl+TabCtrl+⇧Tab | Next / previous tab |
⌘1…9Ctrl+1…9 | Jump to the nth tab |
⌘F | Find & replace in the active sheet |
⇧⌘C | Copy the current line's result |
⇧⌘S⇧⌘L | Copy a share link for the active sheet |
⇧⌘E | Export the active sheet |
⇧⌘I | Import a sheet |
⇧⌘⌫ | Clear the active sheet |
About
Math Notes is a browser-based inline calculator, inspired by Numi. Its source is open — see the GitHub repository.
Calculations run on mathjs, an extensible math library for JavaScript, and currency conversion rates come from the European Central Bank via Frankfurter.
Your sheets stay on your device: they are saved in your browser's storage and are never sent to a server.