Mortgage Payoff Calculator
The month your mortgage actually ends — and how much sooner an extra payment, a yearly lump or a one-off would end it.
The address carries whatever you changed, so anyone opening it sees these numbers. Nothing is saved on our side.
Paid off in
30 years 1 month
Around November 2056. Add an extra payment below to see what moves it.
- $2,205
- Principal and interest
- 30 years 1 month
- November 2056
- 30 years 1 month
- $0
- $0
- $453,887
What each extra amount is worth
Interest avoided, and how much sooner the loan ends. Every extra dollar goes straight against the principal, so it cancels all the future interest that dollar would have accrued.
| Extra each month | Interest saved | vs yours | |
|---|---|---|---|
| Nothing extrayoursThe scheduled term | $0 | — | |
| $100/moPaid off 3 years 9 months sooner | $66,545 | −$0 more in total | |
| $200/moPaid off 6 years 6 months sooner | $114,053 | −$0 more in total | |
| $300/moPaid off 8 years 8 months sooner | $150,122 | −$0 more in total | |
| $500/moPaid off 11 years 10 months sooner | $201,905 | −$0 more in total | |
| $1,000/moPaid off 16 years 7 months sooner | $275,021 | −$0 more in total |
Is biweekly actually a trick?
It is one extra payment a year, described more excitingly.
Paying half the mortgage every two weeks means 26 half-payments a year, which is 13 monthly payments rather than 12. That is the entire mechanism — there is no compounding advantage and no lender magic. This calculator models it as exactly that, so switching between “biweekly” and adding a thirteenth payment spread monthly gives the same answer.
It is a genuinely good idea, and worth knowing you can get the same result by paying $184 extra a month without changing anything with your servicer — and without the fee some of them charge to set it up.
How this calculator works
A month-by-month simulation rather than a formula, because four different kinds of extra payment have to agree with each other.
Each month the balance accrues interest at the annual rate divided by twelve. The payment covers that interest first; everything left, plus any extra, reduces the balance.
Extra monthly, extra annual, a one-off and biweekly all run through the same loop rather than four separate formulas, so they cannot disagree — and biweekly comes out identical to adding a thirteenth payment, which is what it is.
The final payment is trimmed so the balance lands on exactly zero rather than overshooting, the way a servicer does it. A payment at or below the first month’s interest is reported as never clearing the loan, rather than simulated for a century.
What is assumed
- A fixed rate for the rest of the loan.
- Every extra payment is applied to principal in the month it is made.
- No escrow, no mortgage insurance, no prepayment penalty.
A worked example
$340,000 left at 6.75% with thirty years to run, and $300 a month extra.
| Scheduled payment | $340,000 at 6.75% over 360 months |
|---|---|
| Interest on the schedule | Over the full term |
| Paid off instead in | 257 months |
| Sooner by | 361 − 257 |
| Extra paid in | $300 × 257 |
| Interest never paid | 453,887 − 303,765 |
$77,100 put in, $150,122 avoided. That is not a return in the investment sense — it is the removal of interest that would otherwise have accrued on money you no longer owe. On a long loan the effect is roughly double the money committed, and it is the single most reliable thing an ordinary borrower can do with spare cash at a rate like this.
Questions people ask
Arithmetically it turns on whether your expected after-tax investment return beats your mortgage rate. At 6.75% that is a demanding hurdle, and unlike a market return the saving is certain. But this is not only an arithmetic question: a paid-off house changes what a job loss means, and people who value that are not being irrational. Run the numbers, then decide which risk you would rather carry.
It is one extra payment a year with better marketing. Paying half your mortgage every two weeks means 26 half-payments, which is 13 monthly payments rather than 12. There is no compounding advantage. It works, and you can get exactly the same result by adding a twelfth of your payment each month — without whatever fee a servicer charges to set biweekly up.
Usually, but say so explicitly. Some servicers apply unlabelled extra money to the next month's payment instead, which does nothing for the balance. Mark it as a principal-only payment, and check the following statement to confirm the balance dropped by the full amount.
Rarely on modern US residential mortgages, but not never — some non-qualified and older loans carry one, usually within the first few years. Check your note before making a large one-off payment. It will be a specific clause, not something you have to infer.
No. It works on principal and interest only, because that is what extra payments actually affect. Your escrow for tax and insurance continues regardless and is not part of the balance being cleared.
Related calculators
An estimate on principal and interest only. It excludes escrow for tax and insurance, mortgage insurance, and any prepayment penalty your note may carry.