Mortgage Payoff Calculator

Written byOleh Soloninupdated 25 September 2026

Currency

Remaining mortgage balance

Annual interest rate, %

Remaining term (months)

Prepayment mode

Recurring extra payment

Regular extra amount added at the selected frequency.

Advanced options

Extra payment frequency

One-time lump-sum payment

One-time extra principal payment in the selected month.

Month for lump-sum payment

Result

Baseline monthly payment

$1,936.32

Accelerated monthly payment

$2,136.32

Baseline payoff term (months)

300

Accelerated payoff term (months)

239

Months saved

Interest saved

$71,027.35

This result is informational only and is not professional advice.

Base interest cost$300,896.22

Interest saved$71,027.35

Base scenario

300 mo ? $1,936.32 / mo

With extra payment

239 mo ? $2,136.32 / mo

Balance trend

Month 1$279,441.01

Month 48$249,289.31

Month 95$210,027.00

Month 142$158,901.22

Month 189$92,327.33

Month 236$5,637.54

Schedule with extra payments

Long schedules are grouped for easier scanning

Period	Payment	Interest	Principal	Balance
1-12	$25,635.85	$18,716.22	$6,919.63	$273,080.37
13-24	$25,635.85	$18,233.68	$7,402.17	$265,678.20
25-36	$25,635.85	$17,717.50	$7,918.35	$257,759.84
37-48	$25,635.85	$17,165.31	$8,470.53	$249,289.31
49-60	$25,635.85	$16,574.63	$9,061.22	$240,228.09
61-72	$25,635.85	$15,942.75	$9,693.10	$230,534.99
73-84	$25,635.85	$15,266.81	$10,369.04	$220,165.95
85-96	$25,635.85	$14,543.73	$11,092.12	$209,073.83
97-108	$25,635.85	$13,770.23	$11,865.62	$197,208.21
109-120	$25,635.85	$12,942.79	$12,693.06	$184,515.15
121-132	$25,635.85	$12,057.65	$13,578.20	$170,936.95
133-144	$25,635.85	$11,110.78	$14,525.07	$156,411.88
145-156	$25,635.85	$10,097.88	$15,537.96	$140,873.91
157-168	$25,635.85	$9,014.35	$16,621.49	$124,252.42
169-180	$25,635.85	$7,855.27	$17,780.58	$106,471.84
181-192	$25,635.85	$6,615.35	$19,020.50	$87,451.34
193-204	$25,635.85	$5,288.97	$20,346.88	$67,104.46
205-216	$25,635.85	$3,870.09	$21,765.76	$45,338.70
217-228	$25,635.85	$2,352.27	$23,283.58	$22,055.12
229-239	$22,787.74	$732.62	$22,055.12	$0.00

Overpayments and lump sums: the new term, the new payment and the interest saved

See how extra mortgage payments shorten the loan and cut interest: monthly, quarterly or yearly overpayments and a one-off lump sum, with a comparison of a shorter term against a lower payment.

An extra payment goes straight to the balance, and no interest is charged on that part again. This calculator compares your mortgage as it stands with your plan: regular overpayments every month, quarter or year, and a lump sum in a month you choose. It shows the new payoff date or the new payment and how much interest you avoid.

For each plan you can choose whether the overpayment should shorten the term or lower the monthly payment, and see the difference straight away.

How to use

Enter the remaining balance, the rate and the remaining term in months; your latest statement shows all three.
Enter a regular overpayment and how often you make it, or 0 for none.
Add a one-off lump sum and the month you will pay it in the extra fields.
Choose whether to shorten the term or lower the payment, and compare the term, payment and interest saved.

What monthly overpayments save

Example: a balance of 280,000 at 6.76% with 25 years left, a payment of 1,936.32 and 300,896.22 of interest to come. Paying an extra 200 a month and keeping the payment the same clears the loan in 239 months instead of 300 and saves 71,027.35 in interest.

Balance 280,000 at 6.76% over 300 months, overpayments used to shorten the term. Worked out with this calculator.
Extra per month	New term	Months saved	Interest saved
100	266 months	34	40,823.33
200	239 months	61	71,027.35
500	186 months	114	128,766.63
1,000	138 months	162	178,192.47

Shorter term or lower payment

After an overpayment the lender either keeps the payment and the loan ends sooner, or recalculates a lower payment over the remaining term. Shortening the term saves more, because the balance stays lower for longer. A 10,000 lump sum in month 12 saves 37,181.13 and 24 months when it shortens the term, but only 10,237.63 when it lowers the payment, to 1,866.05.

Timing and frequency

The earlier an overpayment goes in, the more interest it removes, because the balance and the interest are highest at the start of the loan.

Frequency matters much less than the total: 200 every month saves 71,027.35, while 2,400 once a year saves 67,932.57. The gap is the interest charged while the money waits to be paid in.

Before you overpay

Check the mortgage terms for any limit on overpayments or an early repayment charge, and ask the lender whether an overpayment reduces the term or the payment by default. Keep an emergency fund separate: money paid into the mortgage is hard to get back out.

Lenders accrue interest daily, so the schedule they send after an overpayment can differ slightly from the monthly calculation here.

What this calculator shows

The payment and term with and without overpayments
How many months come off the mortgage
How much interest you avoid
The new payment when overpayments are used to lower it

What to keep in mind

The rate is fixed, with interest charged monthly at the annual rate ÷ 12; daily accrual can make small differences.
Overpayments are made with the regular payment and go entirely to principal; a lower payment is recalculated over the remaining term.
Fees and early repayment charges are not included.

FAQs

Is it better to shorten the term or lower the payment?

Shortening the term saves more interest. In the example, a 10,000 lump sum in month 12 saves 37,181.13 when it shortens the term and 10,237.63 when it lowers the payment.

How much does an extra 100 a month save?

On 280,000 at 6.76% with 25 years left, 40,823.33 of interest and 34 months. Enter your own balance, rate and term to see your figure.

When is the best time to overpay?

As early as possible, while the balance and the interest on it are at their highest.

Monthly or yearly overpayments?

For the same total, monthly is slightly better: 200 a month saves 71,027.35, 2,400 once a year saves 67,932.57.

Should I overpay the mortgage or save?

Compare the mortgage rate with what your savings earn after tax. If the mortgage rate is higher, overpaying usually saves more, but keep an emergency fund first, since overpayments are hard to take back.

Are there charges for paying off early?

That depends on your mortgage terms. Check them for overpayment limits or early repayment charges before you pay extra.

Why is my lender's figure different?

Lenders accrue interest daily and apply overpayments on specific dates, so their schedule can differ slightly from this monthly calculation.

Worked example

An extra 200 a month

Input: Balance 280,000; rate 6.76%; 300 months left; 200 extra each month; shorten the term

Output: 239 months instead of 300; 71,027.35 of interest saved

Note: The payment with the overpayment is 2,136.32. Raising the overpayment to 500 a month would cut the term to 186 months.

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