How Much Does One Extra Mortgage Payment a Year Save?
Making one extra mortgage payment per year is one of the most recommended personal finance strategies — but actual savings depend on your balance, rate, and loan stage. This guide gives the exact numbers.
Why One Extra Payment Works
A 30-year mortgage = 360 monthly payments. Making 13 payments per year instead of 12 means overpaying by 1/12 of the annual total, applied directly to principal. Because interest is calculated on the outstanding balance, this principal reduction eliminates every future interest charge on that amount for the remaining term.
Exact Savings: $300,000 at 6.5% APR
Standard 30 years: $1,896/month × 360 = $682,560 total. Interest: $382,560.
With 1 extra full payment ($1,896) per year: pays off in approximately 25.5 years. Cuts 4.5 years. Interest saved: approximately $52,000.
That is $52,000 saved from 26 extra payments over the loan’s life — each extra payment saves an average of $2,000 in interest.
3 Ways to Make the Extra Payment
Method 1 — Annual lump sum: one extra full payment per year, specified as principal-only. Best applied at year start when balance is highest.
Method 2 — Bi-weekly payments: pay half your monthly payment every two weeks. 26 half-payments = 13 full payments automatically. No annual memory required.
Method 3 — Monthly addition: divide monthly payment by 12 and add to every payment. On $1,896, add $158/month. Easiest to budget.
Q: Extra payments or invest the money?
A 6.5% mortgage means extra payments earn a guaranteed 6.5% return. S&P 500 historically returns 10-13% (not guaranteed). If you have a fully funded emergency fund and can tolerate investment risk, investing may win long-term. Extra mortgage payments beat HYSA (4.5-5.0%) clearly.
Q: Does this hurt credit score?
No. Extra payments have no negative credit impact. Paying off the mortgage completely at end closes the account — minor temporary dip, but you are mortgage-free.
How the Savings Change at Different Loan Stages
The timing of when you start making extra payments significantly affects how much you save. Early in a 30-year mortgage — when the outstanding balance is highest and each payment is mostly interest — extra payments eliminate the largest interest charges. Later in the loan, when the balance is low and each payment is mostly principal, extra payments save proportionally less.
On a $300,000 mortgage at 6.5% APR: adding one extra full payment ($1,896) per year starting in year 1 saves approximately $52,000 over the loan life. Starting the same extra payment in year 10 saves approximately $28,000. Starting in year 20 saves approximately $8,000. The earlier you start, the larger the compounding effect.
This does not mean waiting is pointless — $28,000 saved from year 10 onwards is still $28,000 worth keeping. But if you have the capacity to start now, every year of delay costs thousands in cumulative interest.
What to Tell Your Mortgage Servicer
Mortgage servicers — the companies that collect your monthly payments — are required by the Real Estate Settlement Procedures Act (RESPA) to apply your payments as instructed. However, if you do not specify, most servicers will apply overpayments to the next month’s scheduled payment rather than to principal.
When making an extra payment, include a written instruction (email, secure message, or payment memo) stating: “This additional payment of $[amount] is to be applied to the principal balance of the loan. It is not an advance payment on future instalments.”
Check your account online 3-5 business days after the payment posts to confirm the principal balance decreased by the extra amount. If your servicer applied it incorrectly, dispute it in writing immediately with a reference to your original instruction.
The 15-Year vs Extra Payment Trade-Off
A 15-year mortgage saves approximately the same total interest as a 30-year mortgage with one extra payment per year — but with important differences. The 15-year mortgage commits you to the higher payment contractually. Missing a payment has legal consequences. The extra-payment strategy on a 30-year is voluntary — in a financial emergency, you can simply stop making the extra payments without consequence and revert to the standard schedule.
For borrowers who want the interest savings of a 15-year mortgage but prefer the flexibility of a lower contractual obligation, the 30-year mortgage with voluntary extra payments is typically the better structural choice. The interest savings are similar; the risk profile is significantly lower.
Enter your balance, rate, and extra payment amount: 1onlinecalculator.com/mortgage-calculator/
Disclaimer: All calculations are estimates for educational purposes. Actual rates and terms vary by lender, credit profile, and state. Use the free calculator linked above for your specific numbers.