Mortgage Refinance Calculator
Calculate your new monthly mortgage payment, lifetime interest savings, and closing costs when refinancing your home loan to a lower interest rate.
What this calculator does
The Mortgage Refinance Calculator estimates your result instantly from the values you enter, using standard mortgages formulas. Calculate your new monthly mortgage payment, lifetime interest savings, and closing costs when refinancing your home loan to a lower interest rate. Calculations run in your browser, so nothing you type is sent to a server, and the output is an estimate for planning rather than financial advice.
About Mortgage Refinance Calculator
The Mortgage Refinance Calculator helps homeowners evaluate whether refinancing their mortgage makes financial sense by comparing monthly payments, closing costs, and lifetime savings.
Formula & Mathematical Calculation
Monthly Savings = Current Monthly P&I - New Monthly P&I
Lifetime Net Savings = Remaining Current Payments - Total New Payments - Closing Costs
Calculation Example
Example: $300k balance @ 7% ($2,120/mo) refinanced to 5.5% ($1,703/mo) with $4,500 closing costs → Saves $416.97/mo and $18,485 Net Lifetime Savings.
Key Benefits
- Calculates exact monthly cash flow improvement after refinancing
- Analyzes total lifetime interest reduction across loan terms
- Accounts for paying closing costs out of pocket vs. rolling into the loan balance
- Compares shortening terms vs. lowering payments
- 100% free and private calculation
How to Use this Calculator
-
Enter Current Mortgage Details
Input current balance, interest rate, and remaining years. -
Specify New Loan Offer
Enter new interest rate, loan term, and closing costs. -
Review Comparison & Savings
Click Calculate to see monthly payment differences and total interest saved.
Assumptions & Limitations
What the calculation assumes
- Every value you enter is treated as an exact, known amount.
- Rates and contributions are assumed to stay constant for the whole period unless the form asks for them separately.
- Results use standard financial formulas and ignore fees, penalties and promotional terms that are not entered above.
- Inflation, tax changes and market volatility are not modelled unless a field for them is provided.
- Amounts are unit-agnostic: results are returned in the same currency you enter.
What it does not cover
- Mortgage Refinance Calculator produces estimates for education and planning, not a quote, offer or professional advice.
- Real-world outcomes differ when fees, taxes, rounding rules or provider-specific terms apply.
- Local regulations and tax rules vary by country and change over time; verify current rules for your jurisdiction.
- Figures are only as accurate as the inputs you supply — check them before acting on the result.
- For decisions with lasting financial impact, confirm the numbers with a qualified professional.
Frequently Asked Questions
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Next step: browse the full Mortgages calculators or read the related guides for context before you decide.