Transparent calculation
How the calculator works
The principal-and-interest payment uses the standard fixed-rate amortization formula. The calculator then adds monthly estimates for property taxes, homeowners insurance, PMI when applicable, and HOA dues.
Extra payments are applied to principal after the scheduled monthly principal-and-interest payment. Taxes, insurance, PMI, and HOA are excluded from the interest-savings comparison because they do not reduce the mortgage balance.
Read formulas, assumptions and sources