Car Refinance Calculator: See Your New Payment, Savings and Break-Even
Enter your current payoff amount, APR and months left, then the new APR, term and any fees. The calculator shows your new monthly payment, the interest on each loan, the total cost of refinancing against keeping your loan, the month you break even on upfront costs, and a warning when a longer term makes a lower payment cost more overall.
Maintained by Archie Chang · Formulas checked October 28, 2026 · Methodology & sources
Your loan and the new loan
APR is held to 0-40%, terms to 1-96 months and dollar amounts to $1,000,000. Check your contract for the real fees and any prepayment penalty.
Your estimated refinance result
- Current monthly payment
- $497.70
- New monthly payment
- $469.70
- Monthly payment savings
- $28.00
- Interest left on the current loan
- $3,889.60
- Total interest on the new loan
- $2,545.66
- Keep the current loan: total payments
- $23,889.60
- Refinance: payments plus upfront costs
- $22,645.66
- Estimated total saved (keep the current loan minus refinance)
- $1,243.94
- Break-even on upfront costs ($100.00)
- Break-even: Month 4
- New loan amount
- $20,000.00
This compares nominal dollars and does not account for the time value of money.
This is an estimate, not a loan offer. Your current payment is calculated from the balance, APR and months you entered, so it can differ from your actual bill.
Current loan: first 12 months
| Month | Payment | Interest | Principal | Balance |
|---|---|---|---|---|
| 1 | $497.70 | $150.00 | $347.70 | $19,652.30 |
| 2 | $497.70 | $147.39 | $350.31 | $19,301.99 |
| 3 | $497.70 | $144.76 | $352.94 | $18,949.05 |
| 4 | $497.70 | $142.12 | $355.58 | $18,593.47 |
| 5 | $497.70 | $139.45 | $358.25 | $18,235.22 |
| 6 | $497.70 | $136.76 | $360.94 | $17,874.28 |
| 7 | $497.70 | $134.06 | $363.64 | $17,510.64 |
| 8 | $497.70 | $131.33 | $366.37 | $17,144.27 |
| 9 | $497.70 | $128.58 | $369.12 | $16,775.15 |
| 10 | $497.70 | $125.81 | $371.89 | $16,403.26 |
| 11 | $497.70 | $123.02 | $374.68 | $16,028.58 |
| 12 | $497.70 | $120.21 | $377.49 | $15,651.09 |
| Total | $5,972.40 | $1,623.49 | $4,348.91 | $15,651.09 |
New loan: first 12 months
| Month | Payment | Interest | Principal | Balance |
|---|---|---|---|---|
| 1 | $469.70 | $100.00 | $369.70 | $19,630.30 |
| 2 | $469.70 | $98.15 | $371.55 | $19,258.75 |
| 3 | $469.70 | $96.29 | $373.41 | $18,885.34 |
| 4 | $469.70 | $94.43 | $375.27 | $18,510.07 |
| 5 | $469.70 | $92.55 | $377.15 | $18,132.92 |
| 6 | $469.70 | $90.66 | $379.04 | $17,753.88 |
| 7 | $469.70 | $88.77 | $380.93 | $17,372.95 |
| 8 | $469.70 | $86.86 | $382.84 | $16,990.11 |
| 9 | $469.70 | $84.95 | $384.75 | $16,605.36 |
| 10 | $469.70 | $83.03 | $386.67 | $16,218.69 |
| 11 | $469.70 | $81.09 | $388.61 | $15,830.08 |
| 12 | $469.70 | $79.15 | $390.55 | $15,439.53 |
| Total | $5,636.40 | $1,075.93 | $4,560.47 | $15,439.53 |
How the calculator works
Both loans use standard fixed-rate amortization with monthly compounding. In plain words: the monthly rate is the APR divided by 12. The level monthly payment is the loan amount times the monthly rate, divided by one minus (one plus the monthly rate) raised to the power of minus the number of months. At 0% APR there is no interest, so the payment is the loan amount divided by the number of months.
- Current payment: worked out from your payoff amount, current APR and months remaining, not read from your statement.
- New loan amount: the payoff amount, plus any cash-out, plus the costs if you roll them in.
- Total cost comparison: all remaining payments on the current loan, against all payments on the new loan plus any costs you pay upfront, minus any cash-out you receive.
- Break-even month: the first month in which the payment you save adds up to your upfront costs. It is counted only over the months your current loan has left, and shows no break-even if the new payment is not lower.
- Rounding: amounts are kept in whole cents and rounded half to even. Each month’s interest is rounded, and the last payment clears the balance exactly.
When refinancing usually saves money
A refinance tends to pay off when the new APR is lower than the old one and you keep the term close to the months you have left. A longer term lowers the payment but adds months of interest, which is why the calculator compares total cost and flags an extended term.
Fees and prepayment penalties. Lender fees, title and registration fees and any penalty for paying off the old loan early depend on your contract and lender. Check your current loan agreement and the new lender’s disclosure, then enter the amounts above.
Credit checks. Lenders may use a soft check to show a preliminary offer and a hard check when you formally apply, but this varies by lender, so ask before you apply.
Title transfer. A refinance usually means the new lender becomes the lienholder on your vehicle’s title. The steps and fees depend on your state and lender.
Refinancing and the car loan interest deduction
If you deduct car loan interest, a refinance has a limit. The IRS final regulations (T.D. 10054) say:
“If a taxpayer refinances an SPVL (refinanced loan), the resulting indebtedness (new loan) is an SPVL if the new loan is secured by a first lien on the APV with respect to which the refinanced loan was incurred. The amount of the new loan that is an SPVL is limited to the outstanding balance of the refinanced loan as of the date of the refinancing.”
As that sentence is worded, cash-out, and fees you roll into the new loan, make the new loan larger than the old balance, and the extra amount falls outside the limit. See the car loan interest deduction calculator for who qualifies and how the cap works.
Car refinance calculator FAQ
When does refinancing a car loan usually save money?
It usually saves money when the new APR is lower than your current APR, the fees are small compared with the interest you would avoid, and you do not stretch the loan much longer than the months you have left. Enter your numbers above: the total cost comparison shows whether the interest you save is larger than the costs you pay and the extra months you take on.
How does the calculator work out the payment?
It uses standard fixed-rate amortization with monthly compounding. The monthly rate is the APR divided by 12, and the level payment is balance times rate divided by (1 minus (1 plus rate) to the power of minus months). At 0% APR the payment is the balance divided by the number of months. Money is kept in whole cents and rounded half to even, and the last payment clears the balance exactly. Your current payment is calculated from your balance, APR and remaining months, so it can differ from your actual bill.
What is the break-even month?
It is the first month, within the months your current loan has left, in which what you have saved on payments adds up to the fees you pay upfront. A shorter term with a higher payment can still break even late in the old loan, once the new loan has ended and the old payments would have continued. If you roll the fees into the new loan and the payment falls, there is no upfront cost to recover, so the break-even is immediate. If the savings never add up to the fees before your current loan would have ended, the calculator shows that there is no break-even.
Why can a lower monthly payment still cost more?
A longer term spreads the balance over more months, so each payment is smaller but you pay interest for longer. When the new term is longer than the months you have left and the total cost goes up even though the payment goes down, the calculator shows an extending-the-term warning. Compare the total cost, not only the monthly payment.
What about fees, prepayment penalties and the title?
Lender fees, title and registration fees and any prepayment penalty on the old loan all vary, so check your current loan contract and the new lender’s disclosure for the actual amounts. A refinance usually involves moving the lien on your title to the new lender, and the steps and fees depend on your state and lender, so ask your lender and your state motor vehicle agency. Enter the amounts in the calculator and choose whether you pay them upfront or roll them into the new loan.
Will refinancing a car loan involve a credit check?
Usually. A soft credit check is generally used to show a preliminary offer, and a hard credit check generally happens when you formally apply, but which one a lender uses and when varies, so ask before you apply. This calculator does not check your credit and its results are an estimate, not a loan offer.
Does refinancing change the car loan interest deduction?
It can. The IRS regulations (T.D. 10054) say that if you refinance a qualifying loan, the new loan can qualify only if it is secured by a first lien on the same vehicle, and the amount that counts is limited to the outstanding balance of the refinanced loan on the date of the refinancing. That outstanding balance can differ from the payoff amount this calculator asks for, for example because of accrued interest. As that sentence is worded, any cash-out, and any fees rolled into the new loan, make the new loan larger than that balance, so that extra amount is outside the limit. Under the regulation's wording, only a refinanced SPVL can produce a new SPVL, so refinancing a loan that did not qualify in the first place does not make it qualify. Use the car loan interest deduction calculator for the federal rules.