← All projects
Alloy calculator
An offline PWA that tells a jewelry workshop what metal to melt to hit a target gold fineness. Used by working jewelers.
Built: October 19-20, 2026UI in Russian
What it is
A mobile-first offline PWA that tells a jewelry workshop what metal to melt to hit a target gold fineness (585, 750 or 999) from the scrap on hand. It has three modes: what to melt, adjust an existing fineness, and predict what a mix gives. Light and dark theme, and a history of the last 20 calculations.
Who it's for
Master jewelers and casters.
The problem it solves
Remove manual paper calculations and mistakes when mixing alloys.
My role
Solo project: design and development.
Value
In real use by the head of the workshop and other jewelers, who say it is more convenient than calculating on paper.
Stack
- JavaScript
- HTML
- CSS
- Service worker
- GitHub Pages
- Node test runner
Highlights
- Exact integer-milligram arithmetic instead of floating point.
- A "cut one lot" search that uses up the fewest stock pieces.
- Every result is re-checked against the target.
- 34 unit tests on a DOM-free solver.
Links
khanapin-t.github.io/alloy-calc
Screenshots