Mortgage Affordability
Understand what a home actually costs each month, over the full life of the loan, and what extra payments can do to both numbers.
Extra payments (optional)
Run the numbers with additional monthly payments, a one-time lump sum, or both. Leave at zero to see the standard loan.
Added to every monthly payment
Single extra payment toward principal
Which month the lump sum is applied
Enter values above to see a projection.
Educational calculator. Does not include PMI, HOA fees, utilities, or maintenance. Actual loan terms and taxes vary. Not personalized financial or lending advice.
About this calculator.
This tool estimates the monthly cost of a mortgage including principal, interest, property tax, and homeowners insurance. It also shows the total interest that will be paid over the life of the loan, and what changes when you apply extra payments.
A few notes on how to use it well. The monthly payment shown does not include private mortgage insurance, which typically applies when the down payment is less than twenty percent of the purchase price. It also excludes HOA dues, utilities, and ongoing maintenance, all of which matter in a real affordability picture. A common rule of thumb is to plan for roughly one percent of home value each year in maintenance costs on top of the mortgage payment.
On extra payments: even modest amounts added to principal can change the loan meaningfully over time. The compounding math behind interest works in both directions. What looks like a small weekly coffee budget added to the payment each month can save years off the loan and tens of thousands in interest.