Mortgage Payoff Calculator

See how many months to clear your loan and the interest it costs.

Current balance

Monthly payment

Annual interest rate

Results update as you type.

Months to payoff

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Total interest—

This calculator is for illustrative purposes only. Actual rates, fees and terms vary by lender. Consult a qualified financial adviser before making borrowing decisions.

How it works

A mortgage payoff calculator answers two questions every borrower eventually asks: how long until this loan is gone, and how much interest will it cost me along the way? By entering your current balance, your monthly payment, and your interest rate, you get the number of months remaining until the balance hits zero, plus the total interest you will hand the lender before you are free of the debt. The result is powerful because it makes the effect of your payment size tangible. Every dollar above the minimum goes straight to principal, and because interest is charged on the shrinking balance, paying a little extra each month can shave years off the loan and save a striking amount of interest. Running the numbers at your current payment, then at a higher one, shows exactly how much time and money accelerating your payoff would buy. The calculation works by inverting the standard amortization formula. Normally that formula sets a payment for a fixed term; here we know the payment and solve for the term instead, using a logarithm to find how many months of payments drive the balance to zero. One important guardrail: if your monthly payment does not exceed the interest accruing each month, the balance never falls and the loan can never be paid off, so the calculator returns no result in that case to flag an impossible scenario.

Formula

Months = −ln(1 − balance × r ÷ payment) ÷ ln(1 + r), where r = annual rate ÷ 12

The monthly interest rate r is the annual rate divided by twelve. Each payment first covers the interest accrued on the remaining balance, and whatever is left chips away at principal. Solving the amortization equation for the number of payments gives the logarithmic formula shown, which returns how many months it takes to reach a zero balance. Multiplying the payment by that many months and subtracting the starting balance reveals the total interest paid over the life of the loan.

Source:Standard amortization formula

We review all our tools from time to time to ensure accuracy.

Worked example

Current balance:200000Monthly payment:1200Annual interest rate:5

A $200,000 balance at 5% paid down at $1,200 a month takes about 285 months, roughly 24 years, to clear. Over that time you pay about $142,170 in total interest on top of the principal.

How to use this calculator

1
Enter your values
Enter current balance, monthly payment and annual interest rate.
2
Adjust the options
Fine-tune any options to match your situation.
3
Read your result
Months to payoff updates instantly as you type — no button to press.

Frequently asked questions

Why does paying a little extra save so much interest?

Interest is charged on your remaining balance, so any payment above the interest due reduces principal immediately. A smaller balance then accrues less interest the following month, which compounds in your favour over time. Even a modest extra amount each month can cut years off the loan and save tens of thousands in interest, because you are attacking the principal that would otherwise keep generating interest for decades.

What happens if my payment is too low to pay off the loan?

If your monthly payment is less than or equal to the interest that accrues each month, none of it reaches the principal and the balance never shrinks. In that situation the loan mathematically never pays off, and the calculator returns no result to flag the problem. It is a warning that your payment must exceed the monthly interest, ideally by a healthy margin, for the debt to actually decline.

Does this calculator account for escrow, taxes, or insurance?

No. It works purely on the loan's principal and interest, so enter only the portion of your payment that goes toward the mortgage itself, not the amount collected for property taxes, homeowners insurance, or private mortgage insurance in escrow. Using your full escrow-inclusive payment would overstate how fast the loan shrinks, so isolate the principal-and-interest figure for an accurate payoff timeline.

How is total interest calculated?

Once the calculator knows how many months it takes to reach a zero balance, it multiplies your monthly payment by that number of months to get the total amount you will pay, then subtracts the starting balance, since that portion is principal you originally borrowed. What remains is the interest. This shows the true lifetime cost of the debt and how dramatically it falls when you shorten the payoff period.

Should I pay off my mortgage early or invest instead?

It depends on your interest rate, expected investment returns, tax situation, and appetite for risk. Paying off a mortgage delivers a guaranteed return equal to your interest rate and peace of mind, while investing might earn more but carries uncertainty. Many people balance both. Use this calculator to see the guaranteed interest savings from early payoff, then weigh that against what the same money might earn elsewhere.