How to Use This Calculator
Enter your current loan's remaining balance, interest rate, and remaining term. Then enter the APR and term you're considering for the refinanced loan. The calculator instantly shows your new monthly payment, monthly savings or increase, and how much more or less total interest you'd pay over the new term.
When Refinancing Makes Sense
Your Credit Score Has Improved
The most common reason to refinance is qualifying for a lower rate than you had when you originally financed the vehicle. If your credit score has risen since you took out the loan — even by 50–100 points — you may be eligible for a meaningfully lower APR. On a $20,000 balance, dropping from 9% to 6% over 48 months saves roughly $1,500 in interest.
Market Rates Have Fallen
Auto loan rates move with broader interest rate conditions. If you financed during a high-rate period and rates have since declined, refinancing lets you capture those savings without waiting for your current loan to run out.
You Need to Lower Monthly Payments
Refinancing to a longer term reduces monthly payments even without a rate reduction. This can ease short-term cash flow pressure, but watch the total interest column: a longer term at the same rate almost always increases total interest paid. Use this calculator to see the trade-off clearly before committing.
You Can Afford a Shorter Term
If your financial situation has improved and you can handle a higher payment, refinancing to a shorter term at a lower rate is the fastest way to reduce total interest. Even keeping the same term but lowering the rate saves a significant amount — and shortening it further compounds those savings.
When Refinancing May Not Help
Your Loan Is Nearly Paid Off
Most of the interest on an auto loan is front-loaded. If you're in the final 12–18 months of repayment, nearly all of each payment goes to principal. Refinancing restarts the interest-heavy early period on the new loan, often costing more than it saves. Check the interest savings figure — if it's small or negative, stay the course.
Your Vehicle Is Old or High-Mileage
Most lenders cap refinancing at vehicles under 7–10 years old and with fewer than 100,000–150,000 miles. An older, high-mileage vehicle may not qualify, or may only qualify at rates comparable to your current loan.
You Have Negative Equity
If you owe more than the vehicle is worth, some lenders will decline to refinance. Those that will may charge a premium rate to compensate for the higher risk. Use our Negative Equity Calculator to assess your position before applying.
How to Qualify for a Better Rate
Lenders primarily use your credit score, debt-to-income ratio, and loan-to-vehicle-value ratio to set your rate. To improve your chances: pay down other debts before applying, check your credit report for errors, and avoid opening new credit accounts in the months before you refinance. Prequalifying with at least three lenders — credit unions often offer the best auto loan refinance rates — lets you compare real offers without affecting your credit score more than once.
Frequently Asked Questions
How much can I save by refinancing my auto loan?
Savings depend on your remaining balance, the rate difference, and your remaining term. As a benchmark: on a $20,000 balance with 48 months remaining, dropping from 9% APR to 6% APR saves roughly $1,500 in total interest, and about $30 per month. The larger the remaining balance and the bigger the rate drop, the more you save. Use this calculator with your actual numbers to get a precise figure.
When is the best time to refinance a car loan?
The best time to refinance is when your credit score has improved significantly, market interest rates have dropped, or both — ideally within the first 12–36 months of your loan when the most interest is still ahead of you. Refinancing in the final year of a loan rarely saves money because you've already paid most of the interest. Avoid refinancing immediately after purchase; lenders prefer the vehicle to have some payment history.
Does refinancing a car loan hurt your credit score?
Refinancing causes a hard credit inquiry, which typically drops your score by 5–10 points temporarily. Multiple applications within a 14–45 day window (depending on the scoring model) are usually counted as a single inquiry, so shopping multiple lenders in a short period limits the impact. The score dip is usually recovered within a few months of on-time payments on the new loan.
Where can I get the best auto loan refinance rates?
Credit unions consistently offer some of the lowest auto refinance rates — often 1–2% below bank rates for members with good credit. Online lenders such as LightStream, PenFed Credit Union, and RefiJet are also competitive and let you prequalify without a hard inquiry. Always compare at least three offers before committing, and use this calculator to verify the total interest savings — not just the monthly payment.
Related Calculators
- Auto Loan Calculator — Compare monthly payments and total interest across different loan terms and rates.
- Negative Equity Calculator — Check if you're upside-down on your loan before applying to refinance.
- Lease vs. Buy Calculator — Weighing your next vehicle? Compare the true cost of leasing versus buying.
- Auto Lease Calculator — Estimate monthly lease payments if you're considering switching from owning to leasing.