Loan Refinance Calculator – Savings, Breakeven & Interest Comparison

Compare your current loan against a refinance offer. See new monthly payment, monthly savings, breakeven time after closing costs, and total interest saved—instantly.

Input-Validated
Instant Updates
Visual Comparison
Monthly Savings (Estimate)
$0

Monthly Payment Comparison

This chart compares your current monthly payment vs the new payment estimate. Use breakeven to judge if upfront costs are worth it.

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Refinance Inputs

Enter your remaining balance and terms. Compare against a new rate/term, including any closing costs, to estimate savings and breakeven.

This tool is commonly used globally (mortgages and refinancing are widespread), so default currency is USD. You can switch to INR or GBP anytime from the menu.
$250K
Use the outstanding principal you still owe (not the original loan amount). You can find this on your latest statement.
7.25%
Enter the nominal annual rate (APR). For mortgages, use the note rate; for other loans, use the stated APR.
25Y
If your loan is in months, convert: months ÷ 12. This tool models standard amortization with fixed monthly payments.
5.75%
A lower rate usually reduces interest cost, but breakeven depends on closing costs and how long you keep the loan.
25Y
“Keep Same” uses the remaining term for a clean rate comparison. Choose “Custom” to model a reset term (e.g., 30 years).
$4.5K
Include lender fees, appraisal, title/registration, and any points. If costs are rolled into the loan, your effective savings can change.
Breakeven
—
Interest Saved
$0
Monthly Savings (Estimate)
$0
Current Payment $0
New Payment $0
Breakeven Time —
Total Interest (Current) $0
Total Interest (New) $0
Total Interest Saved $0

Smart Tips

Breakeven is typically closing costs ÷ monthly savings. If you plan to sell/refinance again before breakeven, savings may not justify the fees.
If you reset to a longer term, your monthly payment might fall, but total interest can rise even at a lower rate.
Compare offers using a consistent basis: the same remaining term is the cleanest apples-to-apples comparison.
Consider prepayment flexibility and penalties. Lower rates help most when you keep the loan long enough.
Run a scenario with zero fees and then with realistic fees to see how sensitive the decision is to closing costs.

Monthly Payment Comparison

Same chart optimized for mobile. Use the details panel for breakeven and interest totals.

How to Use Loan Refinance Calculator

1

Select Currency

Choose USD, INR, or GBP from the menu. This changes how amounts are displayed (symbol + formatting).

2

Enter Current Loan Details

Provide remaining balance, current APR, and remaining years. The calculator uses standard fixed-rate amortization.

3

Enter Refinance Offer

Fill in new APR, choose whether to keep the same term or reset, and add closing costs/fees.

4

Review Savings & Breakeven

Compare monthly payment change, breakeven time, and interest saved. Use the chart for quick visual comparison.

Understanding Loan Refinance Calculation

What is Loan Refinance?

Loan refinancing means replacing your existing loan with a new loan—often at a different interest rate, a different remaining term, or both. The goal is usually to reduce monthly payments, reduce total interest over time, or change loan structure.

How is Loan Refinance Calculated?

This tool compares two amortizing loans (current vs new). For each scenario, it computes the fixed monthly payment based on principal, APR, and term. Then it estimates total interest paid over the remaining term and evaluates monthly savings and breakeven time after closing costs.

Core Formulas Used

Monthly interest rate: r = APR / 12 (with APR expressed as a decimal).
Number of payments: n = years × 12.
Monthly payment (amortizing loan): PMT = P × r × (1 + r)n / ((1 + r)n − 1) (if r > 0).
Total interest over term: Total Interest = PMT × n − P.
Breakeven (months): Closing Costs ÷ Monthly Savings (only if savings > 0).

Factors Affecting Refinance Savings

Uses & Benefits

Decision support

Understand whether a refinance offer makes financial sense based on breakeven time and interest savings.

Offer comparison

Compare offers by changing new APR, term, and fees to identify the most cost-effective structure.

Payment planning

See the expected monthly payment change so you can budget with confidence.

Cost transparency

Quantify the impact of closing costs on breakeven rather than relying on rate alone.

Frequently Asked Questions

Why does a longer new term sometimes increase total interest even with a lower rate?
Extending the repayment period increases the number of interest-charging months. Even at a lower rate, more payments can lead to more total interest paid over the life of the loan.
What if my refinance costs are rolled into the loan balance?
Rolling fees into the loan increases principal, which increases the new monthly payment and total interest. For accurate modeling, add rolled costs to the “Remaining Loan Balance” before comparing.
Does the calculator include taxes, insurance, or escrow?
No. It compares principal + interest (P&I) under standard amortization. Mortgage payments often include property tax, insurance, HOA, or escrow, which can affect your actual monthly outflow.
Is breakeven always a reliable decision rule?
Breakeven is a useful heuristic, but not the only factor. Consider flexibility (prepayment penalties), expected time in the property/loan, and whether you are resetting amortization back to earlier years.
Why does changing currency not change the numeric results?
Currency selection changes display formatting (symbol and thousands grouping). It does not perform FX conversion because refinance decisions depend on the local currency of your loan.

Trust & Notes

Privacy Friendly

All calculations run locally in your browser.

Transparent Math

Uses standard amortization formulas for fixed monthly payments.

Input Validation

Guards against invalid values and edge cases (zero-rate loans).

For Estimation

Actual lender terms, compounding, and fees can vary.

Disclaimer: This refinance calculator provides an estimate using a standard fixed-rate amortization model and assumes the remaining balance is refinanced into a new fixed-rate loan. Actual offers may include adjustable rates, lender credits, points, different compounding conventions, escrow components, taxes/insurance, penalty clauses, and rounding rules. This tool is informational and does not constitute financial advice.