| Original | With Extra | |
|---|---|---|
| Monthly payment | — | — |
| Total payments | — | — |
| Total interest | — | — |
| Payoff date | — | — |
| Interest saved | — | — |
Why a small extra payment saves so much interest
The reason paying a little extra works so well comes down to how mortgages are built. In the early years, almost all of your payment goes to interest, not principal. On a 30-year loan at 7%, your first payment might put less than a quarter toward actually reducing what you owe. Every extra dollar you send, though, goes entirely to principal — and that dollar stops accruing interest for the entire remaining life of the loan.
That's the quiet magic here. An extra $100 a month isn't just $100 — it's $100 that would have generated interest every month for potentially decades. Compound that across hundreds of payments and the savings run into the tens of thousands. Try it above: even a modest extra amount usually shaves years off the payoff date.
The three ways to attack the principal
- A little extra every month — the easiest to stick with. Rounding a $1,430 payment up to $1,500 is nearly painless and adds up fast.
- One extra payment a year — often from a tax refund or bonus. On a 30-year loan this alone can cut roughly 4–5 years off the term.
- A one-time lump sum — inheritance, work bonus, sale of something. Applied early in the loan, its impact is enormous because it kills the most interest-heavy years.
Critical detail: when you send extra money, tell your lender to apply it to principal. Many payment portals have an "additional principal" field. If you don't specify, some lenders just apply it toward your next payment — which does nothing to reduce interest. If you pay by check, write "principal only" on the memo line.
When you should NOT pay extra
Paying down your mortgage faster is satisfying, but it isn't always the smartest move. Skip the extra payments if:
- You don't have an emergency fund. Money sent to the mortgage is locked in the walls — you can't get it back without selling or refinancing. Keep 3–6 months of expenses liquid first.
- You carry higher-interest debt. A 22% credit card balance costs you far more than a 7% mortgage. Kill that first.
- You're not maxing employer 401(k) matching. A 50% match is an instant 50% return — no mortgage prepayment beats that.
Common questions
Is there a penalty for paying my mortgage off early?
Most modern loans have no prepayment penalty, but check your paperwork — a few still do, especially on older or non-standard loans. It'll be listed in your loan documents.
Is paying extra better than refinancing?
They solve different problems. Refinancing lowers your rate; extra payments shorten the term at your current rate. If rates have dropped a lot, refinance first, then apply extra payments to the new loan.
Should I do biweekly payments instead?
Biweekly payments produce almost the same result — 26 half-payments equals 13 full payments a year, one extra. But you can achieve the same thing for free by adding 1/12 of your payment each month, without any lender program or fee.