An auto loan refinance calculator shows exactly how much you save per month and in total interest by refinancing your car loan at a lower rate. Enter your current loan details and a new rate to see your payment savings and total interest reduction instantly.
Loan Details
Most auto refinances have $0-50 in title transfer fees
Monthly Savings
Current Payment
New Payment
Savings Breakdown
Enter your current loan and new rate, then click Calculate Savings.
How to Use the Auto Loan Refinance Calculator
The auto loan refinance calculator computes your exact monthly payment savings and total interest reduction when you refinance at a lower rate. Unlike generic savings estimates, it uses the precise amortization formula for both your current and proposed loan.
Step 1: Find Your Current Loan Balance
Log in to your lender's online portal or call them for your current payoff balance. This is slightly lower than the remaining principal shown on your statement because interest accrues daily. Use the payoff balance — not the original loan amount — for the most accurate results.
Step 2: Get a Rate Quote
Check rates at your current bank, credit unions (often the best rates), and online lenders like LightStream, PenFed Credit Union, or Capital One Auto. Many offer pre-qualification with a soft credit pull that doesn't affect your score. Target a rate at least 1.5-2 percentage points below your current rate for refinancing to make sense.
Step 3: Compare Total Interest, Not Just Monthly Payments
Some refinance offers extend your loan term to lower your payment — but total interest paid can actually increase. This calculator shows both monthly savings and total interest across the full remaining term, so you see the complete picture. The most financially optimal refinance reduces both your payment and total interest.
When Refinancing Makes the Most Sense
Refinancing delivers the biggest savings when: your credit score has improved 50+ points since your original loan; you financed through a dealer (who often mark up rates 2-3% above what you qualify for); you have 2+ years remaining on the loan; and rates have dropped since you got your original loan. If you're within 12 months of payoff, the savings usually don't justify the paperwork.
Frequently Asked Questions
When should I refinance my car loan?
Refinancing makes sense when rates have dropped since you got your loan, your credit score has improved significantly (50+ points), or you initially financed at a dealership with a high markup rate. The ideal window is 6-12 months into the original loan — early enough to save meaningful interest, but after your score has had time to recover from the original hard inquiry.
How much can I save by refinancing my car loan?
Savings depend on your rate difference and remaining balance. Dropping from 9% to 5% on a $20,000 balance with 48 months remaining saves approximately $1,700 in total interest and reduces your monthly payment by about $35. Use this calculator for your specific numbers.
Are there fees for refinancing a car loan?
Most auto loan refinances have minimal fees — often just a title transfer fee of $15-$50 depending on your state. Some lenders charge no fees at all. Unlike mortgage refinancing, auto loan refinancing rarely involves appraisal or origination fees, making it relatively low-risk to refinance.
Is this tool free?
Yes, completely free with no signup required. All calculations run in your browser.
Is my data safe?
Yes. Everything runs locally in your browser. No financial information is transmitted or stored.
Does refinancing a car loan hurt my credit?
Refinancing causes a hard inquiry on your credit report, which typically lowers your score by 5-10 points temporarily. However, rate shopping is treated as a single inquiry if done within a 14-45 day window (depending on the scoring model). The long-term benefit of lower interest usually outweighs the temporary dip.