Mortgage Payoff Calculator

See how extra payments accelerate your mortgage payoff and how much interest you save.

100% Free No Sign-Up Calculated in Your Browser

Current Loan Balance

Annual Interest Rate (%)

Remaining Term (months)

25 years 0 months

Extra Monthly Payment

Extra One-Time Payment

Interest Saved

with extra payments

New Payoff Date

—

Original Payoff Date

—

Original Total Interest

New Total Interest

Scenario	Monthly Payment	Payoff (months)	Total Interest	Total Paid

See how making extra monthly or one-time payments toward your mortgage principal shortens your payoff timeline and reduces the total interest you pay — sometimes called a mortgage overpayment calculator.

How It Works

How Mortgage Payoff Calculator Works

Starting from your current balance, rate, and remaining term, the calculator first works out your original payoff timeline and total interest at the standard payment. It then recalculates the payoff using your extra monthly payment and/or a one-time lump-sum payment applied directly to the principal.

Because extra payments reduce the principal faster, less interest accrues each month, which shortens the loan and compounds the savings — the earlier the extra payment is made, the bigger the effect.

The comparison table shows four scenarios side by side — original, extra monthly only, one-time only, and both combined — so you can see exactly how much time and interest each option saves.

Worked Example

See It In Action

A $250,000 balance at 6.5% with 300 months (25 years) remaining, paying an extra $200/month, saves roughly $46,000 in interest and pays off the loan about 6 years sooner than the original schedule.

Real-World Use Cases

Who Uses Mortgage Payoff Calculator and Why

Testing how an extra $100-200 monthly payment toward your mortgage principal shortens your remaining payoff timeline.
Comparing a one-time lump-sum payment against a smaller but consistent extra monthly payment to see which saves more interest.
Deciding whether to combine both a monthly extra payment and a lump sum for maximum interest savings.
Estimating how many years earlier you could be mortgage-free with a specific extra-payment budget.

Common Mistakes

Mistakes to Avoid

Assuming your lender automatically applies extra payments to principal — some lenders apply extra payments to future interest first unless you specifically designate the payment as "principal only," which would make the real-world result differ from this calculator's projection.
Comparing only the one-time lump-sum scenario to the combined scenario without checking the extra-monthly-only option — the calculator shows all four scenarios (original, extra monthly, one-time, and both) precisely so you can see which fits your actual budget best.
Not checking your loan agreement for a prepayment penalty before committing to an aggressive extra-payment plan — most modern mortgages have none, but some do.

Pro Tips

Tips for Best Results

Confirm with your loan servicer that extra payments are being marked "principal only" — this calculator assumes extra payments go straight to principal, which isn't automatic with every lender.
Compare consistent extra monthly payments against a single lump sum — monthly extra payments usually save more over time since they lower the balance every month rather than just once.

Troubleshooting

Fixing Common Problems

My real mortgage balance isn't dropping as fast as this calculator projects after extra payments. — Contact your loan servicer to confirm your extra payments are being applied directly to principal rather than to future scheduled interest — this is a common reason real-world results lag behind the projection.

Glossary

Terms Explained

Overpayment: Another term for an extra payment — paying more than the required monthly amount so more goes toward principal.

Principal-only payment: An extra payment specifically designated to reduce loan principal rather than being applied to future interest.

FAQ

Frequently Asked Questions

Is a mortgage overpayment calculator the same as this?

Yes — "overpayment" and "extra payment" describe the same thing: paying more than your required monthly amount so more of it goes toward principal, cutting the loan term and total interest.

Should I make one big extra payment or add a little each month?

Both reduce interest, but consistent extra monthly payments usually save more over time because they lower the balance every single month rather than just once. This calculator lets you compare both to see which fits your budget.

Will my lender apply extra payments to principal automatically?

Not always — some lenders apply extra payments to future interest first unless you specifically mark the payment as "principal only." Always confirm this with your loan servicer.

Are there penalties for paying off a mortgage early?

Most modern mortgages have no prepayment penalty, but some loans do. Check your loan agreement or ask your lender before committing to an aggressive payoff plan.