Schulrechner
The calculator you know from school
Joris Yidong Scholl ✓ Verified
io.github.CardiJey.schulrechnerThis is a very early version in development. Unlabeled buttons will be implemented in the future, and bugs may be frequent. If you experience issues or have feature requests, please file an issue (link below).
Frustrated by the lack of free, open-source scientific calculators that feel like the ones I am used to, I decided to reverse-engineer my old calculator from school.
With features like:
- input of complex equations,
- output as fractions as well as decimals,
- result storage and reuse,
- selection and editing of equations from input history,
- and support for implicit multiplication (like 5π instead of 5*π),
- this calculator produces math that looks like the math on your paper. That makes it much more suitable for higher-level math in school and university—especially if you've grown accustomed to this kind of interface from a young age and just forgot your calculator at home.
Some additional features include:
- A well-established open-source math.js library as the math engine—so you're not relying on some sketchy, hand-rolled math logic (just my sketchy hand-rolled input method 😛)
- A familiar, intuitive design
- 100% offline usability and fully open source
- Written entirely in HTML, JS, and CSS, which means it is inherently cross-platform, ...
- easy for other web developers to contribute and ...
- admittedly a bit heavy for a calculator. If you're interested in helping make a lighter version (Flutter, Kotlin, etc.), you're very welcome!
Screenshots
Observed history
| App | Change | Version | When ↓ |
|---|
No observed changes yet.
The initial import establishes a baseline. Future version changes will appear here.
Browse the app catalogue →Upstream releases
Release notes supplied by the developer. These dates are not Flathub package publication times.
1.15.05 Jun 2026
- Feature: Added % function
- Feature: Added ON-button
- Feature: Added OFF-button
- Feature: Added Setting to toggle Turn-Off = Close App
- Feature: Web Version can now be installed as a PWA
- Bugfix: (19/21) / (2/7) now results in a fraction
- Tweak: Made F-Droid App Fullscreen
- Tweak: Updated Dependencies
- Tweak: Switched from Inkscape SVG to Plain SVG, resulting in roughly 10% file size reduction
1.14.024 Jan 2026
- Feature: °′‴-button now switches to DMS format
- Feature: Added option to toggle between Deg, Rad and Gra angle modes
- Feature: Added Eng-button for engineering notation
- Tweak: Updated dependencies
1.13.014 Dec 2025
- Feature: °′‴-button now switches to DMS format
- Feature: Added option to toggle between Deg, Rad and Gra angle modes
- Tweak: Updated dependencies
1.12.05 Oct 2025
- Feature: Added config option to prefer decimal results
- Feature: Added mode menu
- Feature: Added CMPLX mode and i
- Feature: Added integration
- Feature: Added differentiation
- Feature: Added setup menu
- Feature: Added Norm and Fix rounding setup modes
- Feature: Added sexagesimal (hours, minutes, seconds) button
- Bugfix: Eliminated rounding errors in trigonometric functions
- Bugfix: Cube root of -1 now computes to -1
- Tweak: Updated dependencies
