Calchorus is 19 free financial calculators for US taxpayers, freelancers, and homeowners — 1099 and self-employment tax, quarterly estimates, Roth IRA, mortgages, and debt payoff. Every tool shows the full breakdown, not just a final number: each line of the math, the 2026 brackets behind it, and why the result moves when you change an input. Mortgage tools pull the 30-year fixed rate weekly from FRED instead of a stale figure. No account, no email, no paywall — just your answer.