🏠 Mortgage Refinance Calculator with Break-Even (US)

Calculate your mortgage refinance savings, monthly payment changes, and break-even point with this tool designed for United States homeowners.

Last updated: 18 October 2026

Mortgage Refinance Calculator: Compare Your Loan, Break-Even Month and Lifetime Interest

This refinance calculator helps US homeowners compare an existing fixed-rate mortgage with a refinance offer. It shows the new monthly principal and interest payment, the monthly change, closing costs, the break-even month, remaining interest on the current loan, total interest on the new loan, and the net lifetime change after costs. You enter your own balance, rates, and quote figures — the tool does not list or recommend rates.

Scope: Fixed-rate, fully amortizing loans only. Adjustable-rate loans, interest-only loans, FHA/VA/USDA streamline programs, mortgage-insurance changes, escrow changes, and tax effects are outside this calculator. Rates you enter are your own quote or assumption, not an offer from Varnda.

Mortgage calculator refinance: enter your loan details

Current loan

Enter the payoff balance from your latest statement.

Fixed rate on your existing loan. Use three decimals if your statement shows them.

Months left on the current loan. Example: 28 years = 336 months.

Optional. Leave blank to use the calculated payment.

New loan offer

Your own quote or assumption. This calculator does not provide or verify rates.

A longer term can lower the payment but raise lifetime interest.

Closing costs and options

Enter the total from your Loan Estimate, or itemize below. Costs vary by state and lender.

Financing costs raises the new principal and the new payment.

One point usually costs 1% of the loan amount. Enter the dollar cost in closing costs above; this field is for reference in the notes.

Extra cash you take at closing. It is added to the new principal. Cash-out terms and eligibility are set by lenders and agencies.

How long you expect to keep the loan

Used for the horizon comparison: cumulative cost over that period including the remaining balance. Example: 10 years = 120 months.

Infographic: how the refinance decision fits together

Four pieces decide whether refinancing saves money
Rate drop (new rate below current rate) Payment saving
Closing costs you must recover Break-even
Term reset (new term longer than remaining) Lifetime cost
How long you keep the loan Horizon

✓ Included in this calculator

  • Fixed-rate level monthly payments
  • Break-even month from cash-paid closing costs
  • Lifetime interest remaining on each loan
  • Cash vs financed closing-cost treatment
  • Horizon cost including remaining balance
  • Optional cash-out arithmetic

✗ Not included

  • Adjustable-rate or interest-only loans
  • FHA streamline, VA IRRRL, USDA streamline rules
  • Mortgage insurance and escrow changes
  • Property tax and income-tax effects
  • Rate quotes, lender recommendations, or qualification

Infographic: break-even month step by step

How break-even is calculated

Monthly saving

Current P&I minus new P&I. A positive number means the new loan costs less each month.

Cash closing costs

Only costs you pay in cash are used in break-even. Financed costs are already inside the new principal.

Break-even = costs ÷ saving

Exact value to four decimals in the detail line; rounded up to the whole month in the headline. If the payment does not fall, there is no break-even.

Cash costs Monthly saving Break-even

Refinancing a mortgage: how the calculator works

This refinancing a mortgage calculator uses the standard level-payment formula for a fixed-rate, fully amortizing loan. All arithmetic runs in your browser. Nothing you type is sent to a server.

Monthly payment (principal and interest)

P = L × r ÷ (1 − (1 + r)−n)

L = principal (loan balance). r = monthly interest rate = annual rate ÷ 12 ÷ 100. n = number of monthly payments.

  1. Current payment. Computed from the current balance, current rate, and remaining months. If you enter a payment override, the engine checks whether it is consistent with those inputs and labels any mismatch as a warning (it does not block the calculation).
  2. New payment. Computed from the new principal (balance plus financed closing costs and any cash-out), the new rate, and the new term in months.
  3. Monthly change. Current payment minus new payment. Positive means a saving; negative means the new loan costs more each month.
  4. Break-even month. Cash-paid closing costs ÷ monthly saving, valid only when the saving is positive. Displayed rounded up to a whole month; the exact value is shown to four decimals in the detail line.
  5. Lifetime interest. Total of all scheduled payments minus principal, using the engine's amortization schedule (payments rounded half-up to the cent; the final payment retires the balance).
  6. Net lifetime change. Remaining interest on the current loan − total interest on the new loan − closing costs paid in cash. When costs are financed, they are already inside the new principal, so they are not subtracted again.
  7. Horizon comparison. Over the months you expect to keep the loan: cumulative payments plus the remaining balance at that horizon, for each loan, plus any cash closing costs on the current-loan side of the comparison as appropriate.

Rounding policy. Payments and each month's interest are rounded half-up to the cent; the final payment retires the balance. Break-even is exact to four decimals in the detail view and rounded up to a whole month in the headline. Rates display to three decimals. Internal arithmetic uses decimal-safe helpers to avoid binary floating-point drift; formatted display does not change the math.

Method & sources. Rules version: refi-engine-2026-10-18. Formula and amortization method as stated above. Official starting points for closing-cost and disclosure context: Consumer Financial Protection Bureau (CFPB) at consumerfinance.gov — Loan Estimate, Closing Disclosure, and Your Home Loan Toolkit materials; eCFR 12 CFR Part 1026 (Regulation Z), including §1026.37 (Loan Estimate), §1026.38 (Closing Disclosure), §1026.36(c) (payoff statements), and §1026.43(g) (prepayment penalties on qualified mortgages). Freddie Mac Primary Mortgage Market Survey (PMMS) may be used as dated national rate context only; it is a purchase-loan survey, not a refinance quote. No source page was opened; every dollar figure here comes from your inputs.

Worked examples (hypothetical inputs)

These examples use fixed hypothetical numbers so you can see how the engine behaves. They are arithmetic demonstrations, not quotes, rates, or offers. Your result depends entirely on the values you enter.

Example A — lower rate, longer term, costs paid in cash

Hypothetical inputs: balance $300,000.00, current rate 7.000%, remaining term 336 months; new rate 6.250%, new term 360 months; closing costs $6,000.00 paid in cash.

The engine produces: current P&I about $2,038.83; new P&I about $1,847.15; monthly saving about $191.68; break-even about 31.3 months (shown as 32 months); total interest on the new loan higher than a same-length comparison because the term was extended by 24 months. A term-reset warning appears because the new term (360) exceeds the remaining term (336).

Example B — same remaining term

Same balance and rates as Example A, but new term = 336 months (the current remaining term) and closing costs $6,000.00 in cash. Extending the loan is avoided; the monthly saving is smaller than a 360-month quote, and break-even is later, but lifetime interest on the new loan is lower because the term is not restarted. No term-reset warning appears.

Example C — financed closing costs

Balance $300,000.00 becomes a new principal of $306,000.00 when $6,000.00 of costs are financed, at 6.250% for 360 months. Cash break-even by the cash-paid method does not apply (no cash costs were paid out of pocket). The horizon comparison includes the larger principal and the higher payment.

Example D — shorter term

Hypothetical: $300,000.00 at 5.750% for 180 months (15 years) produces a higher monthly payment than a 30-year quote at the same balance and usually far less lifetime interest. Use the shorter-term selector to test affordability side by side with a 30-year option.

Common mistakes and key conditions

  • Assuming a lower rate always saves money. Closing costs, a restarted term, and how long you stay decide the outcome. This calculator shows all three together.
  • Ignoring the term reset. A 30-year quote on a loan with 28 years remaining adds two years of payments. The term-reset warning and the same-remaining-term comparison make that visible.
  • Double-counting financed costs. If closing costs are rolled into the new loan, they are already in the new principal. Subtracting them again in the net lifetime line would overstate the benefit. The engine does not double-count.
  • Using break-even past the horizon. If your break-even month is later than the months you expect to keep the loan, you will not recover the cash costs within that window.
  • Comparing payment only, not lifetime interest. A smaller payment can still mean more interest over the life of the loan when the term is extended.
  • Treating the entered rate as available to you. Rates depend on credit, loan-to-value, loan type, points, and the lender. Nothing here is a quote or a statement that you qualify.

FAQ

Should I refinance my mortgage?

There is no universal answer. A refinance is worth evaluating when the monthly saving, over the time you expect to keep the loan, exceeds the closing costs you pay, and when the new term does not undermine your goals. Use this calculator to compare a specific quote with your current loan, then review the Loan Estimate sections your lender must disclose (see CFPB materials on the Loan Estimate at consumerfinance.gov). This tool does not recommend any product or lender.

How much does it cost to refinance?

Refinance closing costs are set by your lender, title company, and state and local rules, and they vary widely. Common items include origination charges, appraisal, title insurance, recording fees, and prepaid interest. Enter the total from your Loan Estimate in this calculator. No fixed percentage is hard-coded here because costs are user-entered and jurisdiction-dependent.

Does refinancing reset my loan term?

Yes, when the new loan's term is longer than the months remaining on your current loan, you are restarting the clock. That can lower the payment while raising total interest over the life of the loan. The calculator shows a term-reset warning and a same-remaining-term comparison so you can see the effect.

Can I roll closing costs into my loan?

Many lenders allow closing costs to be financed into the new principal. That reduces cash needed at closing but increases the new balance, the new payment, and the interest you pay. Toggle the closing-cost treatment to compare paying in cash versus financing; the engine keeps the two paths separate so costs are not double-counted.

What is a cash-out refinance?

A cash-out refinance replaces your existing loan with a larger one and pays you the difference in cash. In this calculator, any cash-out amount you enter is added to the new principal, and the results show the new payment and the cost of that cash over the loan term. Eligibility, loan-to-value limits, and pricing for cash-out loans are set by lenders and agencies and are outside the core comparison. Official consumer guidance on closing documents is available from the CFPB (Closing Disclosure materials at consumerfinance.gov).

What is break-even on a refinance?

Break-even is the month when cumulative monthly savings cover the closing costs you paid in cash. Formula: cash closing costs ÷ monthly saving, shown rounded up to a whole month. If the new payment is higher than the current payment, there is no break-even on payment alone. The exact value appears to four decimals in the detail line under the break-even result.

Does this calculator show current mortgage rates?

No. Rates are inputs you provide from your own quote or assumption. This page does not list, track, or recommend rates, and it does not state that you qualify for any rate. Dated national surveys such as Freddie Mac's PMMS are context only and are purchase-loan averages, not personal refinance quotes.

What about mortgage insurance, taxes, and escrow?

This calculator compares principal and interest only. Property taxes, homeowners insurance, mortgage insurance, and escrow are excluded unless you account for them separately. If a refinance changes your mortgage insurance or escrow, those differences are not captured here and should be reviewed with your lender's Loan Estimate and Closing Disclosure.

Glossary

Break-even point
The month when cumulative payment savings equal the closing costs paid in cash to complete the refinance.
Points (discount points)
Optional fees paid to the lender at closing, often to buy down the rate. One point usually equals 1% of the loan amount. Enter the dollar cost in closing costs; the points field here is a reference note.
Loan Estimate
A standardized disclosure lenders must provide that shows rate, monthly payment, and closing costs for a mortgage offer. Compare your quote against the sections of this form. See CFPB guidance at consumerfinance.gov.
Closing Disclosure
A standardized form that finalizes the loan terms and costs, typically delivered before closing under Regulation Z (12 CFR 1026.38). Review it against the Loan Estimate you received earlier.
Rate and term refinance
Replacing an existing mortgage with a new loan that changes the rate, the term, or both, without taking additional cash beyond the payoff of the current loan (cash-out is a separate branch).
Term reset
When a new loan's term is longer than the remaining term of the current loan, effectively restarting the amortization schedule.

Limitations, exclusions, and assumptions

  • Fixed-rate, fully amortizing loans only. Adjustable-rate, interest-only, and balloon loans are not supported.
  • FHA streamline, VA IRRRL, and USDA streamline programs have their own eligibility and documentation rules and are outside this comparison.
  • Mortgage insurance changes, escrow changes, property taxes, and income-tax effects (including points and interest deductibility) are excluded.
  • Closing costs, title insurance, and transfer or recording taxes vary by state and lender; all cost figures are user-entered. No state fee schedule is applied.
  • Rates are user-entered. Nothing on this page is a rate quote, a statement that you qualify for any product, or a lender recommendation.
  • Horizon results depend on your expected holding period and assume no extra principal payments, refinance-within-refinance, or prepayment penalties.
  • Corrections can be requested through the contact channel published on the Varnda site; no separate review email is claimed here.

Summary

The mortgage refinance calculator on this page compares your current fixed-rate loan with a refinance quote using only the numbers you enter: new payment, monthly change, break-even month, lifetime interest, and the effect of closing costs paid in cash or financed. Adjust the inputs above to test your own quote, then print or copy the results for your records. For the disclosure documents behind any offer, review the Loan Estimate and Closing Disclosure with your lender and the CFPB's consumer materials at consumerfinance.gov.

Mortgage Refinance Calculator with Break-Even (US)
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