Mortgage amortization schedule with extra payments
Every dollar of extra payment is a principal-only dollar: it skips the interest line entirely and deletes balance that would have been charged interest every remaining month of the loan. That compounding-in-reverse is why modest extras move payoff dates by years. The calculator below models three kinds at once — a recurring extra with each payment, a once-a-year extra (tax refund, bonus), and a one-time lump sum — and shows the new payoff date, the interest saved, and both balance curves on one chart.
The table below the calculator is the receipt: an Extra column shows exactly where your additional principal lands, and the year headers show the balance falling ahead of schedule.
Preset: example $350,000 loan with $200/month extra — set your own numbers
Payment-by-payment schedule
| # | Date | Payment | Principal | Interest | Extra | Balance |
|---|
Click a year to expand its payments. Exports and print always include every payment.
How it works
- Open this page — the calculator is already set up for "Mortgage amortization schedule with extra payments". Swap in your own amount, rate and term.
- Read off the payment, the payoff date and total interest. The full payment-by-payment table is right below.
- Add extra payments or switch to biweekly to watch the payoff date move and the interest saved appear.
- Download the schedule as Excel, CSV or PDF — generated on your device; your loan details never leave your browser.
Make sure the money actually hits principal
The classic failure mode isn’t the math — it’s the servicer applying your extra as an early next payment (interest included) or parking it in “unapplied funds”. The fix is boring and effective: pay through your servicer’s portal using its explicit “additional principal” field, or send instructions in writing, then check the next statement to confirm the balance dropped by the full extra amount. Our principal-only payments guide has the exact scripts and what to do when it’s misapplied.
What extras do to a $400,000 loan at 6.5% over 30 years (computed by this site’s engine)
| Item | Detail |
|---|---|
| +$100/month | saves $63,918 interest · paid off 3 yr 2 mo sooner |
| +$200/month | saves $111,893 interest · paid off 5 yr 7 mo sooner |
| +$500/month | saves $205,559 interest · paid off 10 yr 7 mo sooner |
Computed at build time by the same engine that powers the calculator — enter the $400,000 example with each extra amount above and you’ll get exactly these rows. Savings scale roughly with your rate: higher rate, bigger payoff from the same extra.
Good to know
- Timing beats size early on: a $10,000 lump sum in year 2 saves far more than the same sum in year 20, because it cancels more future interest charges. Try both in the one-time field and compare.
- Extra payments shorten the loan but never lower the required monthly payment — if you want a lower payment instead, that’s a recast (see the guide).
- Almost all US mortgages closed since January 2014 have no prepayment penalty under CFPB rules; the rare exceptions are capped at the first three years. Your note has the final word.
Frequently asked questions
Is it better to pay extra monthly or once a year?
Dollar-for-dollar, monthly wins slightly — money arrives sooner on average, so it cancels more interest. But the difference is small compared with the difference between paying extra and not: $100 every month beats $1,200 every December by a little, and both beat waiting. Model each in the calculator; the “interest saved” line settles it for your loan.
Should I pay extra on my mortgage or my car loan first?
Highest rate first, almost always — a dollar of principal kills interest at that dollar’s rate. Compare your two actual rates side by side; car loans often price above mortgages, and they also tend to be daily-simple-interest loans where early money helps immediately. The honest exception: if the mortgage extra keeps you from an emergency fund, fund that first; principal payments can’t be withdrawn later.
Do extra payments change my monthly payment?
No — the required payment is fixed by contract; extras shorten the tail of the loan instead. The schedule above shows this directly: with extras, payments simply stop years earlier. If a lower required payment is the goal, ask your servicer about a recast, which re-spreads the (now smaller) balance over the remaining term for a small fee.