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Mortgage Refinance Calculator

See your monthly savings, break-even timeline, and total interest saved by refinancing your mortgage.

Updated June 2026 · Editorial standards

Your details

$
%
%
$
Monthly savings
$527
Break-even
8 months
Current total cost
$558,215
New total cost
$651,515

Refinancing saves you $527/month. You'll break even on the $4,000 closing costs in 8 months.The new loan term is longer than your remaining term — lifetime costs are higher despite the lower rate.

Cumulative payments — current vs new loan

New loan — principal vs interest

Quick comparison

Current payment$2,326
New payment$1,799
Current total interest$258,215
New total interest$347,515
By the KalkWise Editorial Team Reviewed for accuracy Updated June 2026

What is the mortgage refinance calculator?

In short

To decide whether to refinance, compare your new monthly payment against your current payment and divide the closing costs by the monthly savings to find the break-even point — the number of months until the savings outweigh the upfront cost. If you plan to stay in the home longer than the break-even period, refinancing saves money.

This mortgage refinance calculator compares your existing loan against a new one. It shows your new monthly payment, monthly savings, the number of months to break even on closing costs, and the lifetime interest savings over the full loan term.

How to use this calculator

  1. 1Enter your current remaining loan balance.
  2. 2Enter your current interest rate and the number of months left on the loan.
  3. 3Enter the new interest rate you've been offered and the new loan term.
  4. 4Add the estimated closing costs (typically 2–5% of the loan amount).
  5. 5Review the monthly savings, break-even period, and total lifetime savings.

The formula

M=P·r·(1+r)n(1+r)n−1
The monthly payment (M) is derived from the loan amount, the monthly interest rate, and the total number of payments. Each payment first covers that month's interest; the remainder reduces the principal.
M
— Monthly payment
P
— Principal (loan amount)
r
— Monthly interest rate (annual rate ÷ 12)
n
— Total number of payments (months)

Worked example

The scenario

You have $280,000 remaining at 7.25% with 22 years left. You're offered 6.0% for 30 years. Closing costs are $5,000.

gives

The result

Your monthly P&I drops from $2,104 to $1,679, saving $425/month. You break even on closing costs in about 12 months. Over 30 years you save $47,600 in total interest (net of closing costs).

Common use cases

  • Deciding whether to refinance after rates have dropped
  • Comparing a rate-and-term refinance vs a cash-out refinance
  • Calculating how long you need to stay in your home to benefit
  • Evaluating different loan terms (15 vs 30 years) at the new rate

Limitations & assumptions

  • Does not account for PMI removal, which can add extra savings when refinancing above 20% equity.
  • Closing costs vary widely by lender, state, and loan size — get a Loan Estimate for exact figures.
  • Assumes you keep the new loan to term; actual savings change if you move or refinance again.

Frequently asked questions

Refinancing makes financial sense when your break-even period (closing costs ÷ monthly savings) is less than the number of months you plan to stay in the home. A rate drop of 0.75–1% or more is typically the threshold worth pursuing.

Disclaimer: KalkWise calculators are provided for general informational and educational purposes only and do not constitute financial, investment, tax, or legal advice. Results are estimates based on the figures you enter and the assumptions described above. Actual outcomes will vary. Consult a qualified professional before making financial decisions.