Auto Loan Calculator
Calculate monthly payment, total interest, and first-year amortization schedule.
By Marcus Rivera | Updated April 2026
How Auto Loan Interest Works
Auto loans use amortization, meaning each payment covers both principal and interest — but the ratio shifts over time. In the early months of your loan, the majority of each payment goes toward interest. By the final months, nearly all of it reduces your balance.
Example: On a $25,000 loan at 7% APR for 60 months, your monthly payment is $495. In month 1, roughly $146 is interest and $349 reduces the principal. By month 48, only $36 is interest and $459 reduces principal.
This is why paying extra toward principal in the early months is so powerful — every extra dollar reduces the balance on which future interest is calculated, compounding your savings.
New vs Used Car Loan Rates in 2026
New car loans consistently carry lower interest rates than used car loans. In 2026, typical ranges are:
- New car loans: 5–8% APR for qualified buyers
- Used car loans: 7–12% APR, often 2–3 points higher than new
Why are used rates higher? Lenders view used vehicles as riskier collateral — the car depreciates faster as a percentage of its value, making recovery harder if the borrower defaults. Used cars also have less verifiable history. That said, even at higher rates, a $15,000 used car often costs far less in total interest than a $35,000 new car at a lower rate.
How Credit Score Affects Your Rate
| Credit Score | Approx. APR | Interest on $30K/60mo |
|---|---|---|
| Excellent (750+) | 5–6% | ~$4,000 |
| Good (700–749) | 7–8% | ~$5,700 |
| Fair (650–699) | 10–12% | ~$8,300 |
| Poor (below 650) | 14–18%+ | ~$12,000+ |
The difference between excellent and poor credit on a $30,000 loan can exceed $8,000 in additional interest over 5 years. If your score is below 680, consider delaying your purchase by 6–12 months to improve it first.
Dealer Financing vs Bank / Credit Union
Where you get your loan matters almost as much as your credit score:
Bank / Credit Union
- + Often lower rates (credit unions especially)
- + Pre-approval gives you negotiating power
- + Transparent terms upfront
- - Requires application before shopping
Dealer Financing
- + Convenient, one-stop shopping
- + 0% promotions (on select new models)
- - Dealer marks up the rate (dealer reserve)
- - Harder to compare without pre-approval
0% financing gotcha: Manufacturers offer 0% to move specific models — but these vehicles rarely get cash rebates. If a $3,000 rebate is available or you're buying used, a low-rate bank loan often beats the 0% offer. Always calculate total cost of both options.
Frequently Asked Questions
Does getting pre-approved hurt my credit score?
Pre-approval involves a hard inquiry, which temporarily lowers your score by 5–10 points. However, multiple auto loan inquiries within a 14–45 day window (depending on the scoring model) count as a single inquiry. Shop multiple lenders within that window to minimize the impact.
Can I pay off my auto loan early?
Yes — most auto loans have no prepayment penalty (verify with your lender). Paying extra each month or making lump-sum payments reduces principal faster, which cuts total interest paid. Even one extra payment per year on a 60-month loan can save hundreds in interest.
Is a 72-month auto loan a good idea?
Generally no. While the lower monthly payment is attractive, you pay significantly more in interest, and you'll likely be "underwater" (owing more than the car is worth) for 2–3 years. This creates risk if you need to sell or the car is totaled. Stick to 60 months or less if possible.
What is GAP insurance and do I need it?
GAP (Guaranteed Asset Protection) insurance covers the difference between what your auto insurer pays (current market value) and what you still owe if your car is totaled or stolen. It's most useful when you put less than 20% down or finance a rapidly depreciating vehicle. It's often cheaper through your auto insurer than through the dealership.
Can I refinance my auto loan?
Yes. If your credit score has improved or interest rates have dropped since you took the loan, refinancing can significantly lower your rate and monthly payment. Most lenders require the car to be less than 10 years old with under 125,000 miles. The process is similar to getting a new loan and typically takes 1–2 weeks.