Kalkulo is a free multi-region calculator hub covering tax, salary, savings, loans, and everyday financial, health, everyday life, or personal calculations across France, the US, UK, and Spain, with more regions to come. Every fiscal and social figure is sourced and cross-checked against official government data for each country — not generic averages. No signup, no paywall: just pick your country and calculate. 100+ tools so far, actively maintained and expanding.