Mortgage Calculators

Every mortgage calculator here runs on the same engine: the amortization schedule of a fixed-rate home loan. Each monthly payment first covers the interest accrued on the current balance, and only the remainder reduces principal — so the balance follows a fully deterministic path from the first payment to the last. That one schedule answers more than payoff questions: it fixes the date the balance crosses any threshold, what a lower rate is worth per month, and what every extra dollar of principal changes downstream. Because the schedule is deterministic, a calculator can show each outcome exactly rather than estimate it.

Two of the tools model acceleration. The extra-payments calculator handles any prepayment you control directly — a fixed monthly addition, a one-time lump sum, or both — and puts the original and accelerated schedules side by side: new payoff date, total interest under each, and the difference in dollars and years. The bi-weekly tool models a specific arrangement: half the monthly payment every two weeks, which produces 26 half-payments a year — the equivalent of 13 full monthly payments — so one extra payment happens automatically. If your servicer does not support true bi-weekly drafting, the same effect can be reproduced in the extra-payments tool by spreading one payment across twelve months.

The other two price a loan’s fixed features. The points break-even calculator compares two rate quotes for the same loan — with and without discount points — and reports the monthly saving, the month the points cost earns itself back, and the net saving over the full term. The PMI removal calculator reads two dates off the scheduled balance: the month you can request PMI cancellation at 80% of the home’s original value, and the month termination becomes automatic at 78%, plus the total PMI paid until each. The table below summarizes which tool answers which question.