Mortgage Refinance Calculator
Mortgage refinance calculator: compare your mortgage with a new one, with saving, break-even and interest saved. Free, no sign-up, and it runs in your browser.
Dedicated page: /en/mortgage-refinance-calculator
Default checked 10 Nov 2026: 7.18% (Freddie Mac 30-year fixed average, week ending 5 Nov 2026). Enter the rate from your own quote. Check the current value here.
US closing costs are often 2% to 5% of the loan.
Extra borrowed on top of the balance, paid to you as cash.
Keeping the old payment clears the new loan years early and is usually where the big saving hides.
Principal and interest only: taxes, insurance, PMI and HOA are unchanged by a refinance and are left out. A lower payment from a longer term is not a saving on its own: check the lifetime interest line. Estimate only, not financial advice.
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Quick answer
A mortgage refinance calculator compares your current home loan with a new one. Enter the balance, the current and new rates, the remaining years, the new term and the closing costs, and it shows the monthly saving, the break-even in months, the total interest on each loan, and whether the deal is actually worth it.
About this Mortgage Refinance Calculator
Mortgage refinance calculator: compare your mortgage with a new one, with saving, break-even and interest saved. It is one of the Money and Finance on ToolUstad, and like every tool here it runs entirely in your browser: nothing you type, paste or open is uploaded to a server, and there is no sign-up or usage limit.
What is a mortgage refinance calculator?
Refinancing replaces your current mortgage with a new one, usually at a lower rate. The calculator compares the two loans on the numbers that decide whether the switch pays. On a $320,000 balance at 7.25 percent with 27 years left, the payment is $2,253.42 a month. A new loan at 6.25 percent over 30 years costs $1,970.30, saving $283.13 a month. That looks like a clear win, and on these numbers it is: total interest falls from $410,108 to $389,306, a saving of $20,802, or $15,802 after $5,000 of closing costs.
But the monthly saving alone is a trap. A new 30-year loan lowers the payment even at the same rate, simply because you take longer to pay. The honest check is the lifetime interest line.
Break-even, and why there are two of them
The quick break-even divides closing costs by the monthly saving: $5,000 divided by $283.13 is about 18 months. On the example it is 19 months. With a smaller rate cut the trap can turn a good-looking deal into a loss: at 6.75 percent over 30 years the payment still drops by $177.91 a month, yet you would pay $17,077 more interest than if you stayed put.
Rolling costs in, taking cash out, and keeping the old payment
Paying closing costs in cash is usually cheaper than rolling them into the loan, because rolled-in costs earn interest for the full term. Rolling $5,000 into a 30-year loan at 6.25 percent adds about $6,083 of interest. A cash-out refinance borrows extra on top of the balance and pays it to you as cash, but it is new borrowing, not a saving: taking $50,000 out adds about $60,829 of interest over 30 years and pushes the payment above what you pay today.
Keep paying your old $2,253.42 a month on the new loan and it is gone in 21 years and 8 months, with total interest of $265,889. That lifts the net saving from $15,802 to $139,219, nearly nine times as much from the same refinance.
Best practices
- Compare Loan Estimates, not advertised rates: get one from at least three lenders on the same day, and compare the APR and the fees together.
- Match the term to what you have left: a fresh 30 years on a loan with 27 years left adds three years of interest.
Common mistakes to avoid
- Judging the deal by the monthly payment alone, and missing that the lifetime interest went up.
- Treating cash out as free money. It is new borrowing at mortgage rates, on top of the old balance.
Who is the mortgage refinance calculator for?
Homeowners with a rate quote in hand, borrowers deciding between a 30-year and a matched term, and anyone weighing a cash-out refinance against a home equity loan.
Current value, checked 10 Nov 2026: the default new rate is 7.18%, the Freddie Mac Primary Mortgage Market Survey 30-year fixed average for the week ending 5 Nov 2026, with the 15-year at 6.57%. The rate box is an optional override. Check the current value here.
This calculator is an estimate only, not financial advice. Your actual rate, costs and terms depend on your credit, the property and the lender.
Learn: how to use the Mortgage Refinance Calculator
- Enter your current loan balance, current rate and years remaining.
- Enter the new rate from your quote, the new term and the closing costs.
- Choose whether to pay closing costs in cash or roll them into the new loan, and add cash out if you want it.
- Set how long you will keep the loan, and whether you will keep paying the old amount.
- Read the monthly saving, the break-even, the lifetime interest comparison, the year-by-year table and the verdict.
Features
- Current vs new payment side by side, with monthly saving
- Break-even counted from interest saved, not just costs divided by saving
- Total interest over the life of each loan, and net saving after costs
- Cash-out mode with the new loan amount shown
- Roll closing costs into the loan, or pay them in cash
- Keep-paying-the-old-payment scenario: payoff date and extra saving
- Year-by-year balance table and a plain verdict with the stay horizon
Worked example
You owe $320,000 at 7.25% with 27 years left, paying $2,253.42 a month. A lender offers 6.25% over a new 30-year term with $5,000 of closing costs paid in cash. The new payment is $1,970.30, saving $283.13 a month. Simple break-even is 18 months; counting interest saved, it is 19 months. Total interest falls from $410,108 to $389,306, so you pay $20,802 less, or $15,802 after costs. Keeping the old $2,253.42 payment on the new loan clears it in 21 years and 8 months and lifts the saving to $139,219.
Frequently asked questions
How long does it take to break even on a refinance?
Divide closing costs by the monthly saving for a quick estimate: $5,000 of costs and a $283 monthly saving is about 18 months. The stricter figure counts interest saved instead of payments, which is 19 months on the same numbers.
Is it worth refinancing for a 1% lower rate?
Often, but not automatically. A one-point drop on a large balance with years to run usually pays for itself within two years. The net saving after costs is the number to judge by.
Should I roll closing costs into the new loan?
Rolling costs protects your cash, but you pay interest on them for the life of the loan. Pay cash if you can afford it.
Does refinancing reset my loan term?
Only if you choose a new full-length term. With 27 years left, a fresh 30-year loan adds three years of payments.
Why is your break-even later than costs divided by monthly saving?
When the new loan is longer, part of the lower payment is simply slower principal repayment, not a real saving. Counting only interest saved is honest about that.
What are typical closing costs?
US closing costs are often 2% to 5% of the loan: lender and application fees, appraisal, title and legal fees, and discount points. On a $320,000 loan that is $6,400 to $16,000.
Will refinancing hurt my credit score?
A new application usually means a hard credit check, which can lower your score by a few points for a short time. Credit scoring models generally treat several mortgage enquiries within a short shopping window as one.
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