Most financial calculators are outdated or built for one country. Wealth Calculator Hub covers 5 countries in one place — UK stamp duty, ISA tax savings, US 401(k) limits, Canadian TFSA room, Australian superannuation, FIRE retirement planning, SIP returns, home loans, and more. All 18 calculators are free, updated for 2026 rules, require no sign-up, and show full breakdowns so you can verify every number yourself.