Loan Amortization Calculator

Every fixed-rate loan — mortgage, car, student — runs on the same engine: a constant payment whose mix flips over time from mostly interest to mostly principal. The simulator splits each payment into the slice that pays the bank and the slice that pays the debt, then lets you add an extra payment and watch years of interest disappear.

Free and interactive — no sign-up, nothing to install. Read the full lesson for the plain-language explanation.