The payment that pays off your mortgage by a target date
The payment that clears a loan in fewer years is the ordinary amortization formula with the shorter term. Nothing else about the loan has to change: you pay the higher amount to principal every month and the loan ends on your date.
Target payment = balance × r ÷ (1 − (1 + r)−t)$280,000 × 0.005625 ÷ (1 − (1 + 0.005625)−180) = $2,477.75
| Mortgage-free in | Monthly payment | Extra each month | Interest from now | Interest saved |
|---|---|---|---|---|
| 10 years | $3,215 | $1,335 | $105,809 | $223,467 |
| 12 years | $2,842 | $962 | $129,289 | $199,987 |
| 15 years | $2,478 | $597 | $165,994 | $163,282 |
| 18 years | $2,243 | $362 | $204,423 | $124,853 |
| 20 years | $2,129 | $249 | $230,965 | $98,311 |
| 25 years | $1,935 | $54 | $300,366 | $28,910 |
Halving the time left does not double the payment. Going from 27 to 15 years raises the payment by 32% but cuts the interest still to come by $163,282. To see what a fixed extra amount does instead, use the mortgage extra payment calculator.
Biweekly payments: one extra payment a year
Paying half the monthly payment every two weeks adds up to 26 half-payments, or 13 full payments, a year: one more than the 12 you owe. Here that ends the loan in 22 yr 1 mo instead of 27 yr and saves $70,544 of interest. You get the same result by adding one twelfth of a payment, $156.71, to each monthly payment, without signing up for a biweekly program or paying a fee for one.
| Plan | Monthly cost | Paid off in | Interest from now |
|---|---|---|---|
| Keep the current payment | $1,880 | 27 yr | $329,276 |
| Biweekly (13 payments a year) | $2,037 on average | 22 yr 1 mo | $258,732 |
| Target 15 years | $2,478 | 15 yr | $165,994 |
Paying early vs. refinancing to a shorter term
Refinancing into a 15-year loan locks in the higher payment and often a lower rate; paying extra on the loan you have keeps the lower required payment as a fallback. Freddie Mac's survey put the 15-year average at 6.45% for the week of Nov 12, 2026.[1] On this balance, a 15-year loan at that rate would cost $2,431.41 a month, compared with $2,477.75 to reach the same date on the current 6.75% loan.
The refinance has closing costs, which the CFPB says can be about the same as on your original purchase loan, and its rule of thumb is to refinance only if the savings repay them in about two years.[2] If you might sell within a few years, you may not earn the costs back.[3] The refi calculator runs that comparison with your numbers.
Before you commit to an early payoff
- Prepayment penalties. Most loans have none; where allowed, a penalty is capped and ends after the third year.[4]
- Liquidity. Money paid into the house is hard to get back without borrowing it again, for example with a HELOC.
- Taxes. Less interest paid means less mortgage interest to deduct if you itemize.[5]
- Other debt. Paying down a higher-rate balance first usually saves more per dollar.
Want a lower payment instead?If you have a lump sum and would rather cut the monthly payment than the term, look at a mortgage recast.
Frequently asked questions
How do I calculate how much extra to pay to pay off my mortgage early?
Work out the payment for the shorter term with the amortization formula, then subtract your current payment. For $280,000 at 6.75%, a 15-year payoff takes $2,477.75, which is $597.26 a month extra.
Do biweekly payments pay off a mortgage faster?
Yes, because 26 half-payments equal 13 monthly payments a year. On this loan that saves $70,544 and ends it in 22 yr 1 mo.
How can I pay off a 30-year mortgage in 15 years?
Pay the 15-year payment on your balance and rate every month. On $300,000 at 7.11% that is $2,714.97 instead of $2,018.12.
Is it smart to pay off a mortgage early?
It saves interest at your mortgage rate with no risk, but it ties up cash. Many people first keep emergency savings and pay off higher-rate debt. This calculator shows the savings; whether it fits your finances is your call.