Mortgage Extra Payment Calculator
Find out what paying a little extra each month really saves — in dollars and in years.
United StatesQuick answer
Paying an extra $200 a month on a $320,000, 30-year mortgage at 6.5% saves about $105,429 in interest and pays the loan off 6.6 years early. Every extra dollar goes straight to principal, so it stops interest from being charged on that dollar for the rest of the loan.
Optional.
Interest you save
$105,429
- Paid off sooner by
- 6 yr 7 mo
- New payoff time
- 23 yr 5 mo
- Regular monthly payment
- $2,023
- Payment with extra
- $2,223
- Total interest without extra
- $408,142
- Total interest with extra
- $302,714
Assumes every extra dollar goes straight to principal. Check your lender has no prepayment penalty.
Extra monthly payment on a $320,000 loan at 6.5%, 30 years
| Extra per month | Interest saved | Paid off sooner by | New payoff time |
|---|---|---|---|
| $50 | $33,799 | 2 years | 28 years |
| $100 | $61,698 | 3.8 years | 26.2 years |
| $200 | $105,429 | 6.6 years | 23.4 years |
| $300 | $138,446 | 8.8 years | 21.2 years |
| $500 | $185,552 | 12 years | 18 years |
| $1,000 | $251,400 | 16.8 years | 13.2 years |
How it works
Your regular mortgage payment is fixed, and in the early years most of it is interest. Anything you pay on top goes directly to the principal balance. Because interest each month is charged on the balance, a smaller balance means less interest next month, and the month after — so extra payments made early in the loan save far more than the same amount paid near the end.
The calculator compares two schedules: your loan exactly as agreed, and the same loan with your extra monthly amount and any one-off lump sum. The difference in total interest is your saving; the difference in months is how much sooner you will own the home outright. To see your full payment including tax and insurance, use the mortgage calculator.
Extra payments shorten the loan but keep your monthly payment the same. If you would rather keep the same payoff date and lower the monthly bill, ask your lender about a mortgage recast instead. And if you are still paying private mortgage insurance, extra principal also brings forward the date you can cancel PMI.
Before you pay extra, make sure you have an emergency fund and no high-interest debt — a credit card at 22% costs far more than a mortgage at 6.5%. Compare the guaranteed saving here with what the same money could earn invested, using the compound interest calculator.
More mortgages & home loans calculators
- Mortgage CalculatorSee your full monthly house payment — not just principal and interest — and how much interest you pay over the loan.
- Mortgage Recast CalculatorPay a lump sum, keep your rate, and see how far your monthly payment drops.
- PMI Removal CalculatorWork out exactly when you can stop paying private mortgage insurance — and how to get there sooner.
Frequently asked questions
Is it better to pay extra on the mortgage or invest?
Paying extra earns a guaranteed return equal to your mortgage rate. Investing may earn more over long periods but with risk. Many people do both once they have an emergency fund and no high-interest debt.
How do I make sure extra goes to principal?
Mark the payment as 'principal only' online or in writing. Otherwise some lenders hold it as an early payment of next month's installment instead of reducing the balance.
Is one extra payment a year worth it?
Yes. One extra full payment a year — the same as paying half your payment every two weeks — usually cuts 4 to 5 years off a 30-year loan at today's rates.
Will extra payments lower my monthly payment?
No. The payment stays the same and the loan ends sooner. To lower the payment after a large lump sum, ask your lender to recast the loan.