Mortgage Payoff Calculator
With balance left 285000 usd, interest rate 6.125 percent, months left on the term 288 months, extra you pay each month 300 usd and 1 more field, mortgage payoff comes to 214 months — months until it clears. It is reached in 11 steps, the last of which is log(2191.1368 / (2191.1368 - 285000 * 0.0051042)) / log(1 + 0.0051042), and each one is printed on the page with its numbers filled in. The formula is the one published by CFPB, not an approximation fitted to it.
When a mortgage clears if you pay extra each month, how many years that cuts off the term, and what the interest saved comes to.
Formula and sources checked · How we check
Balance left 285000, Interest rate 6.125, Months left on the term 288 months, Extra you pay each month 300
214 months
Months until it clears for the example below. Editing a field recomputes the calculator below; this figure holds the answer the page was loaded with.
It is written into the HTML rather than drawn by a script, so a search engine reading this page without running JavaScript still finds an answer.
- Payment you owe each month
285000 * 0.0051042 / (1 - pow(1 + 0.0051042, -288))$1,891- Balance after the one-off payment
max(0, 285000 - 0)$285,000- What you actually pay each month
1891.1368 + 300$2,191- Months until it clears
log(2191.1368 / (2191.1368 - 285000 * 0.0051042)) / log(1 + 0.0051042)214.161- Years until it clears
214.16143 / 1217.847 years- Months cut off the term
288 - 214.1614373.839- Interest if you change nothing
1891.1368 * 288 - 285000$259,647- Interest paying extra
2191.1368 * 214.16143 - 285000$184,257- Interest saved
259647.4 - 184256.99$75,390- Extra money you put in
300 * 214.16143 + 0$64,248- Saved per dollar of extra paid
75390.412 / 64248.4291.173
Balance while you overpay
| Year | Balance left |
|---|---|
| Year 1 | $275,910.25 |
| Year 2 | $266,247.85 |
| Year 3 | $255,976.73 |
| Year 4 | $245,058.53 |
| Year 5 | $233,452.51 |
| Year 6 | $221,115.31 |
| Year 7 | $208,000.88 |
| Year 8 | $194,060.26 |
| Year 9 | $179,241.39 |
| Year 10 | $163,488.94 |
| Year 11 | $146,744.10 |
| Year 12 | $128,944.36 |
| Year 13 | $110,023.25 |
| Year 14 | $89,910.12 |
| Year 15 | $68,529.89 |
| Year 16 | $45,802.72 |
| Year 17 | $21,643.77 |
| Year 18 | $352.67 |
The table above groups the 214 months into 18. The amortisation schedule prints every one of them, with the split between interest and principal.
Worked example
$285,000 left at 6.125% with 288 months to run costs $1,891.14 a month. Paying $2,191.14 instead clears it in 214 months — 74 months, just over six years, sooner — and saves $75,390 in interest for $64,248 of extra payments, a dollar saved for every 85 cents put in early.
How to work it out yourself
- 1.Tell the servicer the extra is for principal. Money sent without that instruction is usually held as a prepayment of next month’s bill, which saves nothing — the balance the interest is charged on has to fall for any of this to work.
- 2.Check for a prepayment penalty before starting. They are rare on modern conforming mortgages and not rare on loans taken privately or on some ARMs.
- 3.Compare the interest rate against what the same money would earn elsewhere. Paying down a 6.125% mortgage is a guaranteed 6.125% return with no tax on the gain — good against savings, arguable against a workplace match you are not claiming.
What each extra payment is worth
| Extra you pay each month (usd) | Months until it clears | Years until it clears | Interest saved |
|---|---|---|---|
| 0 | 288 months | 24 years | $0 |
| 50 | 272 months | 22.65 years | $17,004 |
| 100 | 258 months | 21.47 years | $31,731 |
| 200 | 234 months | 19.47 years | $56,052 |
| 300 | 214 months | 17.85 years | $75,390 |
| 500 | 184 months | 15.34 years | $104,373 |
| 750 | 157 months | 13.1 years | $129,507 |
| 1000 | 137 months | 11.45 years | $147,435 |
The first hundred dollars saves more than the fourth: every dollar of principal removes all the future interest it would have carried, and there is more future left at the start.
The formula
- Payment you owe each month
285000 * 0.0051042 / (1 - pow(1 + 0.0051042, -288)) - Balance after the one-off payment
max(0, 285000 - 0) - What you actually pay each month
1891.1368 + 300 - Months until it clears
log(2191.1368 / (2191.1368 - 285000 * 0.0051042)) / log(1 + 0.0051042) - Years until it clears
214.16143 / 12 - Months cut off the term
288 - 214.16143 - Interest if you change nothing
1891.1368 * 288 - 285000 - Interest paying extra
2191.1368 * 214.16143 - 285000 - Interest saved
259647.4 - 184256.99 - Extra money you put in
300 * 214.16143 + 0 - Saved per dollar of extra paid
75390.412 / 64248.429
Source: CFPB — paying off your mortgage faster, US SEC Investor.gov — compound interest
Questions people actually ask
- Is it better to pay extra monthly or make one big payment?
- A dollar paid earlier always saves more, so a lump sum today beats the same money spread over a year. Both beat waiting: the interest you avoid is charged on every month the balance would otherwise have stood.
- What about biweekly payments?
- Half the payment every two weeks is 26 half-payments — thirteen monthly payments a year rather than twelve. On the loan above that clears it 5.8 years early and saves $116,343 in interest. The saving comes entirely from that thirteenth payment, so paying a twelfth extra each month does the same thing without the servicer fee some charge to set it up.
- Should I pay off the mortgage or invest?
- Paying down the loan is a risk-free return equal to the rate, and it is not taxed. An investment has to beat that after tax to win, which a 6% mortgage makes a real contest. Claim any unmatched employer contribution and clear anything at credit-card rates first — both beat either option.
- Does paying extra lower my monthly payment?
- No. It shortens the term instead: the payment stays put and the loan ends sooner. Lowering the payment requires a recast, which some servicers do for a fee after a large principal reduction, or a refinance.
Related
- Mortgage Payment CalculatorMonthly principal-and-interest payment on a fixed-rate mortgage, plus total interest paid over the full term.
- Amortization CalculatorFull payment schedule for a loan, with the option to pay biweekly or add extra each month and see what it saves.
- Refinance CalculatorWhat refinancing saves each month, what it costs to do, and how long you have to stay for it to have been worth it.
- HELOC CalculatorWhat a home equity line of credit costs while you draw on it, and what the payment jumps to on the day the draw period ends.
- Loan Payment CalculatorMonthly payment and total interest on any fixed-rate instalment loan — car, personal or student.
- Credit Card Payoff CalculatorHow many months a card balance takes to clear at a fixed monthly payment, and what the interest costs.
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