See how much interest you save and how many years you cut off your loan by paying a little extra each month.
Even $100/month makes a big difference over 30 years.
How your balance, interest, and principal change each year — with and without the extra payment.
| Year | Balance (no extra) | Balance (with extra) | Interest paid | Interest saved (cumulative) |
|---|
Making extra payments on your mortgage is one of the highest-return, lowest-risk financial moves available to homeowners. Unlike stock market investments, the return is guaranteed — equal to your mortgage interest rate — and the savings compound over the life of the loan.
Every mortgage payment you make consists of two parts: interest and principal. In the early years of a 30-year mortgage, the vast majority of your payment goes to interest. On a $350,000 mortgage at 7%, your first payment of roughly $2,329 breaks down as: $2,042 interest, $287 principal. That means only 12% of your payment actually reduces your debt in month one.
When you make an extra payment and specify it goes toward principal, you skip ahead in the amortization schedule. Less principal means less interest accrues next month, which means more of your regular payment goes to principal — creating a snowball effect that accelerates payoff dramatically.
1. Monthly extra payment — Add a fixed amount every month. Even $50–$100 extra compounds into significant savings over 30 years.
2. Bi-weekly payments — Pay half your mortgage every two weeks instead of once a month. This results in 26 half-payments = 13 full payments per year instead of 12. One free extra payment annually without feeling it.
3. Annual lump sum — Apply your tax refund, bonus, or inheritance directly to principal. A single $5,000 payment in year 3 of a 30-year mortgage saves over $15,000 in interest.
4. Round up your payment — If your payment is $1,847, pay $2,000. The $153 extra goes entirely to principal with no lifestyle impact.
5. Refinance to a shorter term — A 15-year mortgage at today's rates saves massive interest but commits you to a higher payment. Extra payments on a 30-year loan give you the same benefits with the flexibility to stop if needed.
When making extra payments, always mark them as "apply to principal" — either in your lender's online portal payment notes or on your check. Without this instruction, some lenders apply the extra amount toward your next month's payment instead, which saves you no interest at all.
The debate: pay off the mortgage early or invest the extra money instead? The math depends entirely on your mortgage rate vs investment return:
• Mortgage at 7%+ vs market: Pay the mortgage. A guaranteed 7% return (debt elimination) beats a risky market return that averages 7–10% before accounting for sequence-of-returns risk.
• Mortgage at 3–4%: Invest. Historical market returns of 7–10% beat a 3–4% guaranteed return handily over long periods.
• Always get your 401k employer match first — it's an instant 50–100% return that beats both options.