Slopculator Features GitHub Open app

The calculator built for your keyboard.

Type math the way it's written. Get exact answers, statistics, matrices, calculus, graphs and HVAC in one page that runs in your browser and collects nothing.

Open Slopculator View the code on GitHub

Free and MIT licensed · v0.1.0-alpha

Slopculator on a desktop: a sheet of seven lines with a slider, two curves, a normal probability and a matrix determinant, beside a graph of the curves with their zeros and crossings marked. Slopculator on a phone: the same lines above a calculator keypad.

Write it the way it's written.

2x, 3(4 + 5), sin 30, √16, |x|, 5! and x² all mean what they look like. Missing brackets get filled in, and a line that might not say what you meant, like -3^2, gets a one-click rewrite.

  • Exact mode keeps fractions as fractions and shows only proven digits
  • Whole numbers keep every digit, so 25! isn't rounded
  • Ctrl+K finds any of 258 functions by name or by what it does
  1. 0.1 + 0.23/10
  2. sin(30°)1/2
  3. 2^6418446744073709551616
  4. normalcdf(-1, 1)0.682689492137
  5. integral(x^2, x, 0, 3)9
  6. solve(x^2 = 2, x, 1)1.41421356237
  7. 10% of 505

One page for a whole course.

From an algebra worksheet to a stats lab to a duct sizing job. Every function is listed in the function reference.

Lines that share

a = 3 gets a slider. f(x) = x^2 can be called and is graphed. ans is the line above, and line letters refer to earlier answers.

Graphs

y = …, x = …, implicit curves, inequalities, points, piecewise and domains. Hover to trace. Zeros, highs, lows and crossings are marked.

Statistics

Normal, binomial, t, χ², F, Poisson and geometric distributions, regressions, and a normal curve with its probability shaded.

Matrices and calculus

Matrices and vectors, derivatives, integrals, sums and solve, plus number theory, geometry, finance, units and bases.

HVAC

Psychrometrics with altitude, loads and coils, 20 refrigerants, ducts, fans, pumps and pipes, checked against PsychroLib and CoolProp.

Keyboard first

Every control works without a mouse and has a label for screen readers. Two looks, Modern and Retro, in light, dark, OLED black and high contrast.

Nothing leaves your browser.

No account, no analytics, no ads, no cookies. Your sheets and history stay in your browser's storage, and the page makes no network requests once it has loaded.

  • Works offline, and opens full screen from a phone's home screen
  • Download it as one HTML file that runs anywhere
  • Read the privacy policy. It's short.

Web

Open it now

Single file

Download

On your phone

Add it to your home screen

Source code

On GitHub

Open source, top to bottom.

The engine, the app and the tests are on GitHub under the MIT license. Read it, fork it, or send a fix.

Browse the source 
$ git clone https://github.com/Ferro-5G/slopculator
$ cd slopculator
$ npm install
$ npm run dev

Your homework deserves a better calculator.

Slopculator is free, open source and fast. Open it and start typing.

Open Slopculator Download the file