199 calculators · DE/EN · Web & software
Rechnerzentrale
199 calculators for tax, benefits and everyday life – every formula tested against official reference values before it goes live.
- calculators for tax, benefits, finance and everyday life
199
calculators for tax, benefits, finance and everyday life
- until content is visible (LCP, Lighthouse desktop, 24 Sep 2026)
0.55 s
until content is visible (LCP, Lighthouse desktop, 24 Sep 2026)
- bilingual with clean language versions
DE/EN
bilingual with clean language versions
01Starting point
Online calculators are often slow, full of ads and rarely verifiable. The goal: fast calculators whose results can be backed up – even as laws and values change every year.
02Approach
- 01Calculation logic separate from the interface, every formula with a source.
- 02Golden master tests and a value register against official reference values – they block any release that deviates.
- 03Calculation in the browser: no input leaves the device.
- 04Delivered statically for very short load times, installable as a PWA.
03Outcome
A portal with 199 calculators that loads in about half a second, with every formula verified before it goes online.
- Next.js
- TypeScript
- Vitest
- Golden-Master-Tests
- PWA
A similar task on your desk?
In the intro call we tell you how we would approach it – and how quickly you would see results.