Finance & Loans Tools

Compound Interest Calculator opens this category because compounding is the one calculation where intuition reliably fails. Doubling the interest rate does not double your outcome — it changes the curvature of the growth curve, and the gap between monthly and annual compounding on a ten-year investment can be larger than the first year's principal. The tool shows the ending balance, total interest earned, and a year-by-year table so the shape of that curve is visible rather than just implied by a single final number. The compounding-frequency selector covers the eight schedules that actually appear in savings accounts, bonds and loan agreements: daily, weekly, biweekly, monthly, quarterly, biannually and annually. Loan Calculator sits alongside it here from the Math & Calc category: enter a principal, rate and term and it walks the amortisation month by month, splitting every payment into interest and principal so you can see exactly when the balance tips in your favour. Telling a visitor to "compound monthly" without letting them change it is a tool that answers a different question than the one they brought.