Car Affordability Calculator
Find out how much car you can afford based on your monthly budget. Calculate the maximum purchase price, total interest, and total cost of ownership for your auto loan.
A car affordability calculator translates your monthly budget into the maximum realistic vehicle purchase price, accounting for loan term, interest rate, and down payment. Americans now finance the average new car for roughly 68 months at around $740/month — a historic high that has quietly absorbed a growing share of household income. Our free calculator works backward from what you can comfortably pay each month, so you shop with a ceiling in mind rather than letting a dealership stretch your term to fit the sticker price.
The classic guardrail is the 20/4/10 rule: put at least 20% down, finance for no more than 4 years, and keep total transportation costs (payment, insurance, fuel, maintenance, registration) under 10% of your gross monthly income. Few buyers hit all three today, but each you hit reduces risk of being underwater — owing more than the car is worth — and shrinks total cost of ownership. A $35,000 sedan is not really a $35,000 decision; it is more like a 5-year $48,000–55,000 decision once you add financing, insurance, fuel, tires, maintenance, and depreciation.
Depreciation is the single most underestimated cost. A new vehicle typically loses about 20-30% of its value in year one and roughly half its value by year five. This is why certified pre-owned vehicles 2-3 years old often represent the sweet spot: the original buyer absorbed the worst depreciation while warranty coverage remains. Use this calculator to stress-test both new and used scenarios at realistic interest rates. Lease quotes can also be translated to an equivalent purchase price for comparison. This tool is for education only and is not financial advice; insurance costs, registration fees, and taxes vary significantly by state.
Quick answer: With a $500/month budget, a 60-month loan at 6.5% APR, and $3,000 down, you can afford a car priced at roughly $28,600 (about $25,600 financed). Following the 20/4/10 rule — 20% down, 4-year term, payment under 10% of income — keeps you out of underwater territory. This calculator shows the exact max price, total interest, and total cost for your budget.
Inputs
Quick presetsLoan payment only — keep insurance, gas, and maintenance in a separate line of your budget.
Auto terms typically range 36-84 months; 72+ is a yellow flag that balloons interest and keeps you underwater longer. The 20/4/10 rule caps this at 48 months.
Typical auto APR in 2026 runs 6-9% for prime credit; subprime borrowers often pay 12%+. Credit-union pre-approval usually beats dealer financing by 1-2 points.
Target 10-20% of sticker price (20% new, 10% used). Less than 10% sharply raises year-one underwater risk since new cars lose 20-30% of value immediately.
Results
How to use this calculator
Start with **monthly budget for car** — this is strictly the loan payment, not your total transportation budget. If your take-home is $5,500/month, a safe target is about $400-550 for payment alone, with another $200-400 reserved for insurance, gas, and maintenance to stay under the 10% rule.
**Loan term** defaults to 60 months; consider 48 or even 36 if you can swing it, since each extra year of term inflates total interest. Dealers aggressively push 72 and 84 months to fit a payment, but longer terms dramatically increase the risk of being underwater when you want to trade.
**Interest rate** varies by credit score and new vs. used. As of 2026 benchmarks, excellent credit might see 5-7% for new and 6-8% for used; sub-prime borrowers often pay 12%+. Check your credit before shopping and get pre-approved from a bank or credit union — dealer financing is often marked up.
**Down payment** reduces total financed and lowers monthly payment. 20% for new and 10% for used is the traditional floor. The output shows max car price, total interest, and total cost — compare these across scenarios to see the real cost of stretching.
Worked examples
Maria, $70k salary, applying 20/4/10
Maria earns $70,000 gross ($5,833/month). The 10% rule caps total transportation at $583/month. She estimates $180 insurance, $150 gas, and $60 maintenance, leaving $193/month for a loan payment. Entering $193/month at 6.5% APR over 48 months with $3,000 down, the calculator shows a max car price of roughly $11,700. That points her to a reliable 3-4 year old used compact rather than a new SUV. The discipline feels tight but leaves her budget room for savings and avoids underwater risk on a depreciating asset.
The 72-month trap
A buyer considers a $38,000 SUV. At 72 months and 7% with $3,000 down, the monthly payment is about $596 and total interest paid is $8,000. Stretching to 84 months drops the payment to about $528 but pushes total interest past $9,400 and keeps the buyer underwater for nearly the full first 4 years (loan balance > market value). Compressing to 48 months pushes the payment to about $839 — out of budget for most — but total interest drops to $5,200. The calculator makes the tradeoff concrete: each 12 months of term added costs thousands.
EV buyer stacking the $7,500 federal credit
Priya targets a qualifying EV with a $7,500 federal tax credit applied at point of sale as effective down-payment. She pairs it with $2,500 cash, sets a $550/month budget, and models a 60-month term at 6.0% APR (credit union pre-approval). The calculator returns a max car price of roughly $38,500 and total interest near $7,000. She uses the headroom to target a trim she can keep for 8-10 years, where the EV's lower fuel and maintenance costs compound — offsetting its steeper first-year depreciation.
Frequently asked questions
What is the 20/4/10 rule?
A traditional guideline: put at least 20% down, finance for no more than 4 years, and keep total transportation spending (payment + insurance + fuel + maintenance + registration) under 10% of gross monthly income. It biases buyers toward affordable vehicles with manageable total cost of ownership and low underwater risk.
New or used — which saves more?
A 2-3 year old used vehicle typically represents the best value: the original owner absorbed the steepest depreciation (often 20-30% in year one, 40-50% by year three) while much of the useful life remains. Certified pre-owned adds warranty coverage and inspection at a modest premium.
Should I lease or buy?
Leasing offers lower monthly payments and a new car every 2-3 years but builds no equity. Over a lifetime of driving, buying and keeping cars 8-10 years is typically thousands cheaper. Leasing can make sense for business use with tax write-offs or for drivers who value always-new vehicles and want to avoid repair risk.
What is total cost of ownership?
TCO includes purchase price, financing, depreciation, insurance, fuel, maintenance, repairs, registration, and taxes. For a typical new sedan, TCO over 5 years often runs 1.4-1.6x the sticker price. EVs shift the mix — lower fuel and maintenance but higher depreciation and insurance.
How does my credit score affect the rate?
Dramatically. A borrower with 750+ might get 5-6% on a new car, while a 620 score could see 12-15%+. On a $30,000 5-year loan the rate gap between excellent and subprime can exceed $10,000 in total interest. Pull your credit and fix issues before shopping.
Should I pay cash if I can afford to?
If the loan rate exceeds your expected after-tax investment return, paying cash saves more. If you can get 3-4% financing while earning 5% in a high-yield account or expecting 7%+ in the market, financing and investing the cash can come out ahead — at the cost of a monthly payment and additional risk.
What counts as a good down payment?
Traditional guidance is 20% for new and 10% for used. Less than that risks being underwater early in the loan, making it hard to trade or sell without writing a check. Larger down payments reduce monthly payment, total interest, and GAP insurance need.
Should I get the dealer's extended warranty?
Usually no. Dealer extended warranties are often high-margin add-ons that rarely pay out proportional to their cost. If you want extended coverage, compare third-party warranty providers and read the exclusions. For reliable used vehicles with good maintenance records, self-insuring by saving the premium is often cheaper.