Auto Loan Calculator: Total Cost of a Car Loan Including Interest

A $35,000 car loan at 7.5% APR for 60 months means a $700/month payment and $7,000 in total interest. Extend it to 72 months to get the payment down and you pay $9,800 in interest. At 84 months, $11,600.

The monthly payment drops, but the total cost rises every time you extend the term.

Monthly Payment and Total Interest by Term

$35,000 loan at 7.5% APR:

| Term | Monthly Payment | Total Paid | Total Interest | |------|----------------|------------|----------------| | 36 months | $1,087 | $39,132 | $4,132 | | 48 months | $845 | $40,560 | $5,560 | | 60 months | $700 | $42,030 | $7,030 | | 72 months | $602 | $43,344 | $8,344 | | 84 months | $534 | $44,844 | $9,844 |

Each extra year saves $66-$100/month on the payment but adds $1,300-$1,500 in total interest.

How Interest Rate Affects Total Cost

$35,000 loan, 60-month term:

| APR | Monthly Payment | Total Interest | |-----|----------------|----------------| | 3.9% | $643 | $3,598 | | 5.9% | $672 | $5,320 | | 7.5% | $700 | $7,030 | | 9.9% | $742 | $9,520 | | 14.9% | $828 | $14,680 | | 19.9% | $919 | $20,140 |

The difference between 3.9% (excellent credit) and 9.9% (subprime credit) on this loan is $5,922 in interest over 5 years. Improving your credit score before buying is the highest-ROI move available.

Credit Score and Auto Loan Rates (2026)

| Credit Score | Typical New Car Rate | Typical Used Car Rate | |-------------|---------------------|----------------------| | 781-850 (Super prime) | 5.2% | 6.8% | | 661-780 (Prime) | 6.4% | 8.9% | | 601-660 (Near prime) | 8.9% | 13.5% | | 501-600 (Subprime) | 11.9% | 18.9% | | 300-500 (Deep subprime) | 14.2%+ | 21.4%+ |

Rates vary by lender, but the gap between excellent and poor credit on a $35,000 loan is $12,000-$17,000 in interest over 5-7 years.

New vs. Used: Total Cost Comparison

A new $35,000 car vs. a 3-year-old used car at $22,000:

| | New Car | Used Car | |---|---------|----------| | Purchase price | $35,000 | $22,000 | | Loan rate (60 mo) | 6.4% | 8.9% | | Monthly payment | $682 | $456 | | Total interest | $5,900 | $5,360 | | Year 1 depreciation | ~$6,000 | ~$2,500 | | Total 5-year cost | ~$46,900 | ~$29,860 |

The used car costs $17,000 less over 5 years after accounting for higher interest rate on used vehicles and lower depreciation. The new car's first-year depreciation alone exceeds the entire 5-year interest cost on either loan.

Down Payment vs. Monthly Payment Tradeoff

$35,000 vehicle, 7.5% APR, 60 months:

| Down Payment | Loan Amount | Monthly Payment | Total Interest | |-------------|-------------|----------------|----------------| | $0 | $35,000 | $700 | $7,030 | | $3,500 (10%) | $31,500 | $630 | $6,327 | | $7,000 (20%) | $28,000 | $560 | $5,624 | | $10,500 (30%) | $24,500 | $490 | $4,921 |

Every $3,500 extra down payment saves approximately $700 in interest and reduces the monthly payment by $70.

The True Cost of a Car Per Year

Beyond the loan payment, car ownership costs:

| Cost Category | Annual Estimate | |--------------|----------------| | Loan payment ($700/mo) | $8,400 | | Insurance | $1,800-$2,400 | | Fuel | $1,800-$3,000 | | Maintenance + tires | $1,000-$1,500 | | Registration + taxes | $200-$600 | | Depreciation (year 3-5) | $3,000-$4,000 | | Total | $16,200-$19,900 |

A $35,000 car costs $16,000-$20,000 per year to own when all costs are included. A $20,000 used car at the same utilization costs $11,000-$14,000 per year.

Frequently Asked Questions

Should I finance through the dealer or my own bank?

Always get a pre-approval from your credit union or bank before walking into a dealership. The dealer's financing desk earns profit on rate markups — they may quote 8% when you qualify for 6% at your bank. Having your own financing offer gives you leverage. If the dealer beats it, use theirs. If not, use yours.

What is GAP insurance and do I need it?

GAP (Guaranteed Asset Protection) pays the difference between what you owe on the loan and what the car is worth if it is totaled. Most relevant in the first 2 years of a loan with less than 20% down — this is when you are most likely to be "underwater" (owe more than the car is worth). If you put 20%+ down, you likely don't need it.

How much car can I afford?

The 20/4/10 rule: 20% down, finance for no more than 4 years, total monthly car costs (payment + insurance) under 10% of gross monthly income. On $6,000/month gross income, that is a maximum of $600/month for payment plus insurance. That supports roughly a $20,000-$22,000 purchase price with a 4-year loan.