15 vs 30 Year Mortgage Calculator

About this calculator

Choosing between a 15-year and a 30-year fixed-rate mortgage on the same loan amount is fundamentally a trade-off between monthly cash flow and total interest paid. A 15-year loan carries a higher monthly payment because principal is repaid over half the time, but it typically comes with a lower interest rate and a dramatically smaller total interest bill, since amortization spreads far less interest over a shorter payoff period.

Mortgage lenders, financial advisors, and homebuyers use this comparison during loan shopping because the two terms serve different goals: a 30-year term maximizes monthly affordability and frees up cash for other investments or expenses, while a 15-year term builds equity faster and can save tens of thousands of dollars in interest over the life of the loan, at the cost of a stiffer required payment.

This calculator runs the full amortization schedule for both terms on the same loan amount and rate assumptions, showing the exact monthly payment difference and the total interest saved by choosing the shorter term.