Page one covers the calculations everyday life keeps asking for: what a foreign price costs in your currency, what a mortgage or loan really costs per month and in total interest, what VAT adds or hides, and what your salary becomes after tax. Each uses the standard formula a bank or accountant would.
The currency converter pulls live mid-market reference rates from the European Central Bank via the Frankfurter API — the honest benchmark before card fees and spreads. Everything else on the page is pure, transparent arithmetic with the working shown.
Compound interest works for you in savings and against you in debt, and the same mathematics runs both. The compound interest, mortgage and loan calculators share one engine — payment formulas from amortisation maths — so their answers reconcile with each other and with your bank's quote.
Take-home pay uses simplified progressive brackets for six countries — close enough for salary comparisons and offers, clearly labelled as approximate since allowances, local taxes and personal circumstances shift the exact figure. Inflation projections likewise use the rate you choose rather than pretending to know the future.