Extra Mortgage Payment Calculator
See how much time and interest you save by paying a little extra each month.
How to use this calculator
Enter your remaining balance, interest rate, years left on your loan, and how much extra you plan to pay each month. The calculator shows exactly how many months and years you'll shave off your loan and how much total interest you'll avoid.
Does extra payment go straight to principal?
Yes — as long as you're current on your loan and you specify "apply to principal" (or your lender does it automatically). Every dollar applied to principal reduces the balance that future interest is calculated on, compounding your savings over time.
Is it better to pay extra monthly or make a lump sum?
A lump sum saves more interest because it reduces the balance immediately rather than over time. But consistent extra monthly payments are more practical for most budgets and still produce substantial savings. Use our Lump Sum vs Monthly Payment calculator to compare both strategies side by side.
What if I can only pay extra occasionally?
Even sporadic extra payments help — each one permanently reduces your principal. This calculator assumes a consistent extra payment every month. For the occasional lump sum, try the Mortgage Recast Calculator to see if recasting makes sense.
Will my lender apply extra payments correctly?
Most lenders do, but it's worth confirming. When you pay online, look for an option to specify "additional principal." If mailing a check, write "apply to principal" in the memo line and include a separate note. Some servicers require a call to set this up permanently.