Refinance Calculator Online
Compare your current mortgage to a refinance offer and see monthly savings and your break-even month, right in your browser. Estimates only — not financial advice.
The Refinance Calculator runs entirely in your browser — your balance, rates, and closing costs are never uploaded or stored on a server. These are estimates only, not financial advice.
Open the Mortgage Calculator
About Refinance Calculator
Refinance Calculator compares your existing mortgage against a new refinance offer so you can see, at a glance, whether refinancing is worth it. Enter your remaining balance, current rate and months left, then the new rate, term and closing costs — the tool works out the current and new monthly payments, your monthly savings, the break-even month when those savings recoup the closing costs, and the lifetime interest difference between the two loans. It is built for homeowners comparing refi offers from a lender, loan officers running quick what-if scenarios, and anyone deciding whether current rates make a refinance worthwhile. Every figure is computed locally in your browser as you type — your loan numbers are never uploaded. These are estimates only, not financial advice; confirm final numbers with your lender.
Features
- Compares current mortgage payment against a refinance offer side by side
- Calculates the exact monthly savings (or added cost) of refinancing
- Finds the break-even month where savings recover your closing costs
- Shows the lifetime interest difference across both loan terms
- Supports different remaining terms on the current loan and new term on the refinance
- Handles a 0% rate and zero closing costs without errors
- One-click copy of a plain-text summary of all results
- Runs entirely in your browser — your mortgage figures stay on your device
How to use the Refinance Calculator
- Enter your current loan's remaining balance, rate, and months left
- Enter the refinance offer's new rate, new term, and closing costs
- Read the current vs. new payment, monthly savings, and break-even month
- Copy the summary to compare offers from different lenders
Example
Input
$250k, 7%->5.5%, 300 mo, $4k costs
Output
Monthly savings: $232
Break-even: 18 months
A $250,000 balance moving from 7% to 5.5% over 300 months saves about $232 a month, recouping $4,000 in closing costs in 18 months.
Common errors & troubleshooting
- Break-even shows 'Never' even though the new rate looks lower. — Check that the new term isn't much shorter than the current remaining term — a shorter term raises the payment even at a lower rate, which can erase the monthly savings.
- Rate entered as 0.055 instead of 5.5. — Enter interest rates as a percent (5.5 for 5.5%), not a decimal fraction. Entering 0.055 will produce a near-zero payment.
- Monthly savings look too small compared to online estimates elsewhere. — Other calculators sometimes compare the new payment to a fresh 30-year loan instead of your actual remaining months. Enter your true remaining months on the current loan for an accurate comparison.
- Closing costs left blank and break-even shows 0 months. — With no closing costs entered, any positive monthly savings breaks even immediately. Fill in your lender's estimated closing costs for a realistic break-even month.
Frequently asked questions
- What does the Refinance Calculator break-even month mean?
- It is the number of months of monthly savings it takes to recoup your closing costs — calculated as closing costs divided by monthly savings. If you plan to stay in the home past that month, refinancing is likely worth it.
- How does the Refinance Calculator find my monthly savings?
- It computes your current loan's monthly payment from the remaining balance, current rate, and months left, then computes a new payment from the same balance at the new rate and term. Monthly savings is the difference between the two.
- Can the Refinance Calculator handle a shorter or longer new loan term?
- Yes. Set the new term to any number of months — refinancing into a shorter term than you have remaining can raise the payment even at a lower rate, and the calculator reflects that honestly.
- Does the Refinance Calculator send my mortgage numbers anywhere?
- No. All calculations happen locally in your browser as you type. Your balance, rate, and closing cost figures are never uploaded to ArrayKit or anyone else.
- Is the lifetime interest difference the same as total savings?
- It's the difference in total interest paid over the compared terms — a useful second view alongside monthly savings and break-even, especially if the new term is much longer or shorter than what remains on your current loan.
- Is the Refinance Calculator financial advice?
- No. It produces estimates only, based on the numbers you enter and standard amortization math. Always confirm actual rates, fees, and payments with your lender before deciding to refinance.
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