11 professional-grade financial calculators, free forever, no signup: FIRE (Lean/Fat/Barista/Coast variants), compound interest with inflation adjustment, mortgage amortization, debt payoff (avalanche vs snowball), net worth, emergency fund, inflation, investment fees, Rule of 72 and Social Security break-even. Available in English, Italian, German, Spanish and French. Every methodology documented with primary sources (Fed, ECB, IMF). No paywalls, no lead capture — just the math.
