Quick answer
Monthly savings = current payment − new payment, and break-even months = closing costs ÷ savings. Refinancing a $250,000 balance from 7% (28 years left) to 5.5% for 30 years lowers the payment from $1,699.02 to $1,419.47, saves $279.55 a month and breaks even on $4,000 of closing costs in 15 months.
Enter the balance, current rate and remaining term, the new rate and term, and closing costs. The calculator returns the payments, savings, break-even and change in total paid. Use this refinance calculator to check your own figures.
Related tools: APR Calculator: Annual percentage rate of a loan once upfront fees are counted. Down Payment Calculator: Down payment amount and loan size from a percentage. Amortization Calculator: Full amortization schedule with optional extra monthly payments.
How to use the Refinance Calculator
- Enter current balance ($) (above 0).
- Enter current rate (%) (between 0 and 100).
- Enter current remaining term (years) (between 0 and 50).
- Enter new rate (%) (between 0 and 100).
- Enter new term (years) (between 0 and 50).
- Enter closing costs ($) (0 or more). It starts at 0.
- Press Calculate to see the result, and use Reset to start again.
| Input | What to enter | Allowed values |
|---|---|---|
| Current balance | A number, in $ | > 0 |
| Current rate | A number, in % | ≥ 0, ≤ 100 |
| Current remaining term | A number, in years | > 0, ≤ 50 |
| New rate | A number, in % | ≥ 0, ≤ 100 |
| New term | A number, in years | > 0, ≤ 50 |
| Closing costs | A number, in $ | ≥ 0, starts at 0 |
Formula and method
Formula
savings = current payment − new payment; break-even = closing costs ÷ savings
IEEE-754 double precision; money shown to cents, rates to 4 decimals. Results are estimates, not financial advice.
Both payments are standard amortizing payments on the same balance.
Worked examples
These examples are verified: each one is an automated test case that the live calculator must reproduce exactly.
Example 1
Inputs: Current balance = 250000; Current rate = 7; Current remaining term = 28; New rate = 5.5; New term = 30; Closing costs = 4000.
| Result | Value |
|---|---|
| Monthly savings | $279.55 |
| Current payment | $1,699.02 |
| New payment | $1,419.47 |
| Break-even | 15 months |
| Change in total paid (incl. costs) | -$55,861.13 |
Example 2
Inputs: Current balance = 150000; Current rate = 6; Current remaining term = 20; New rate = 6.25; New term = 20; Closing costs = 2000.
| Result | Value |
|---|---|
| Monthly savings | -$21.75 |
| Current payment | $1,074.65 |
| New payment | $1,096.39 |
| Break-even | No break-even |
| Change in total paid (incl. costs) | $7,218.97 |
Example 3
Inputs: Current balance = 200000; Current rate = 6; Current remaining term = 25; New rate = 5; New term = 25; Closing costs = 0.
| Result | Value |
|---|---|
| Monthly savings | $119.42 |
| Current payment | $1,288.60 |
| New payment | $1,169.18 |
| Break-even | 0 months |
| Change in total paid (incl. costs) | -$35,826.82 |
The first line is the headline result (monthly savings). Below it the refinance Calculator lists current payment, new payment, break-even and change in total paid (incl. costs), which describe the same case from other angles. IEEE-754 double precision; money shown to cents, rates to 4 decimals. Results are estimates, not financial advice.
Payment versus total interest
Stretching the term back to 30 years lowers the payment but can raise total interest. The calculator also shows the change in total paid over the life of the loans so you can see both effects.
Break-even
If you will keep the home longer than the break-even time (15 months here), refinancing saves money. A break-even only exists if the payment falls. Consider points, appraisal fees and loss of any rate lock.
How the result changes with current balance
Holding every other input at the first worked example, this table changes only current balance. It shows how sensitive the answer is to that one value; each row was produced by running this calculator.
| Current balance | Monthly savings | Current payment | New payment |
|---|---|---|---|
| 125000 | $139.77 | $849.51 | $709.74 |
| 250000 | $279.55 | $1,699.02 | $1,419.47 |
| 500000 | $559.10 | $3,398.04 | $2,838.95 |
| 1000000 | $1,118.20 | $6,796.09 | $5,677.89 |
What happens with invalid input
These messages are produced by the calculator itself, so you know what to fix.
- Current balance: entering "0" shows "Current balance must be greater than 0." beside that field and no result.
- Current remaining term: entering "0" shows "Current remaining term must be greater than 0." beside that field and no result.
Choosing between the Refinance Calculator and similar calculators
Each row shows what a related calculator on this site asks for and what it returns, so you can pick the one that matches your question.
| Calculator | You enter | It returns |
|---|---|---|
| [APR Calculator](/finance/apr-calculator/) | loan amount, upfront fees and note rate | APR |
| [Down Payment Calculator](/real-estate/down-payment-calculator/) | home price and down payment | Down payment |
| [Amortization Calculator](/finance/amortization-calculator/) | loan amount, interest rate and term | Monthly payment |
| [House Affordability Calculator](/real-estate/house-affordability-calculator/) | annual gross income, other monthly debt payments and down payment | Estimated maximum home price |
| [FHA Loan Calculator](/finance/fha-loan-calculator/) | home price, down payment and interest rate | Monthly payment (P&I + MIP) |
Background: personal finance estimates
Financial calculators project from the numbers you give them. Long-range tools depend on guesses about returns and tax rates that are unlikely to hold exactly, payoff tools assume a fixed payment and rate, and tax or salary results depend on the tax year, filing status and country. Official calculators say their output is for reference only.
For decisions that matter, use conservative inputs and check the figures against your lender, plan documents or a qualified adviser.
Assumptions and limitations
- Break-even only exists if the payment falls
Results are estimates for planning, not financial advice. Lender terms, fees, taxes and rounding rules can change real figures, so confirm important numbers with your lender or a licensed adviser.
If a required value is empty, not a number, or outside its allowed range, the form marks that field with a message and shows no result instead of a misleading number. The automated checks deliberately try invalid entries for current balance and current remaining term to confirm this.
Frequently asked questions
When does refinancing make sense?
When the savings pay back the costs before you move.
Can I refinance to a shorter term?
Yes, enter a shorter new term.
Are taxes and insurance included?
No. The payment is principal and interest only; property tax, insurance and any mortgage insurance would be added.
What does the Refinance Calculator calculate?
Monthly savings and break-even time from refinancing. It returns Monthly savings, Current payment, New payment, Break-even and Change in total paid (incl. costs).
What formula does the Refinance Calculator use?
savings = current payment − new payment; break-even = closing costs ÷ savings. Both payments are standard amortizing payments on the same balance.
What do I need to enter in the refinance Calculator?
You enter Current balance ($), Current rate (%), Current remaining term (years), New rate (%), New term (years) and Closing costs ($).
How is the result rounded or limited?
IEEE-754 double precision; money shown to cents, rates to 4 decimals. Results are estimates, not financial advice. Break-even only exists if the payment falls.
What is an example of a refinance result?
With current balance 250000, current rate 7, current remaining term 28, new rate 5.5 and new term 30, the monthly savings is $279.55.
Can I rely on this calculator for a decision?
Results are estimates for planning, not financial advice. Lender terms, fees, taxes and rounding rules can change real figures, so confirm important numbers with your lender or a licensed adviser. For this calculator in particular: Break-even only exists if the payment falls.
Related calculators
- APR Calculator — Annual percentage rate of a loan once upfront fees are counted.
- Down Payment Calculator — Down payment amount and loan size from a percentage.
- Amortization Calculator — Full amortization schedule with optional extra monthly payments.
- House Affordability Calculator — Estimate the most expensive home your income supports.
- FHA Loan Calculator — Monthly payment with upfront and annual mortgage insurance premiums you enter.
- Mortgage Calculator — Monthly mortgage payment with property tax, insurance and HOA.
- VA Mortgage Calculator — Monthly payment with a financed funding fee you enter.
- Canadian Mortgage Calculator — Monthly payment with semi-annual compounding of the quoted rate.
Sources
- Standard time-value-of-money relations (e.g. Brealey, Myers & Allen, Principles of Corporate Finance)
Content last reviewed 2026-11-04. Formulas and worked examples are checked by automated tests against independently computed values.