Free · offline · no sign-up
Calculating notepad
Write your thinking on the left, get answers on the right. Each line is calculated as you type, with live suggestions for units, conversions and functions you can accept with Tab. Name a line and reuse it as a variable further down, and it understands units and currencies in plain language.
Opens a fresh page with just this tool on it. Everything else is one click away.
How to use it
- 1 Type a calculation, one per line. The answer appears on the right as you go.
- 2 Name a line (like "rent = 1200") and reuse that name in the lines below it.
- 3 Convert as you go: 100 cm to m, 72 °F to °C, 2000 usd to eur with live rates. Start typing a unit or currency and accept the suggestion with Tab.
- 4 Use sum, avg, min, max and clamp with the named lines you want, like sum(rent, utilities, groceries).
Try it like this
Around thirty functions, with autocomplete
- Basic
- sqrt · abs · round · floor · ceil · factorial
- Trigonometry
- sin · cos · tan · asin · acos · atan · atan2
- Hyperbolic
- sinh · cosh · tanh · asinh · acosh · atanh
- Logarithms
- ln · log · log2 · log10
- log is base 10, ln is natural
- Aggregates
- sum · avg · min · max · clamp
- Angles & constants
- degrees · radians · pi · e
Dates work too: today()
and date() support
date literals and date math, like date(A) - date(B) to weeks.
Frequently asked questions
What is a calculating notepad?
A notepad where every line is also a calculation. Instead of clearing a calculator between steps, you write your working out as text and see the result of each line beside it, so you can go back and change an assumption and watch everything below it update.
Is this a free alternative to Soulver?
Yes. The Workbook covers the same core idea: line-by-line calculation with named variables and live unit and currency conversion. It runs free in your browser, and needs no account.
Can it convert units and currencies?
Yes. It handles length, mass, temperature, area, volume, data, speed, energy, power, pressure and time, with natural syntax like "5 ft to cm". Currency conversion uses live exchange rates.
What functions does it support?
Around thirty, including sqrt, abs, round, floor and ceil; the trigonometric and hyperbolic families; log, ln, log2 and log10; sum, avg, min, max and clamp; factorial; and the degrees and radians helpers with the constants pi and e.
Does it suggest what to type?
Yes. As you type a unit, a currency or a function, it shows the likely completion as grey ghost text. Press Tab to accept it, or keep typing to ignore it.
Does it work offline?
Yes for calculations, units and functions. Currency conversion needs a connection the first time it fetches live rates, then keeps working offline from the last rate it cached.
Can I use it inside my notes?
Yes. From any note, press / and choose Calculation to embed a live Workbook block, the same engine running right inside the page.
It is not just this one tool
The calculating notepad is one block inside KontrolRoom, a modular workspace with notes, a calculating workbook, task boards and 20+ other utilities you can arrange on a single canvas. It all runs locally in your browser, works offline and costs nothing.
Explore the full workspace