Calculate how much car you can afford — monthly payment, total cost of ownership, and the 20/4/10 rule check.
Vehicle & Loan Details
Your Income & Ongoing Costs
20/4/10 Rule Check
Total Cost Breakdown
| Cost Item | Monthly | Over Loan Term | 5-Year Total |
|---|
How Car Affordability Is Calculated
Your monthly payment is calculated using standard loan amortization. We then layer in the true cost of car ownership — insurance, fuel, maintenance — to show you the full picture.
- Loan amount: Vehicle price + sales tax + fees − down payment − trade-in equity (trade-in value minus amount owed).
- Monthly payment: Calculated with standard amortization formula at your APR over the loan term.
- 20/4/10 rule: A popular personal finance guideline — 20% down, 4-year max term, 10% max of gross income on car costs.
- Depreciation: New cars lose roughly 15–25% of value in year one and ~50% over 5 years — factored into the 5-year cost estimate.
Actual loan offers depend on your credit score. Always get pre-approved and compare rates from multiple lenders before visiting a dealership.
How to Use the Car Affordability Calculator
- Enter your monthly take-home pay — Use your net income after taxes and deductions, not your gross salary. Your actual car budget should be based on what lands in your bank account each month.
- Enter your monthly debt payments — Include all existing recurring debt obligations: student loans, credit cards, personal loans, and any other installment payments. This helps the calculator assess how much additional debt your budget can realistically absorb.
- Enter your down payment amount — Input the cash you have available to put toward the purchase. A larger down payment reduces the loan amount, lowers the monthly payment, and reduces the risk of going underwater on the loan.
- Enter the loan term — Select your intended repayment period in months: 36, 48, 60, 72, or 84 months. Shorter terms mean higher monthly payments but significantly less total interest paid.
- Enter the interest rate — Input the APR you expect to qualify for based on your credit score. Check current auto loan rates from your bank, credit union, or an online lender before estimating.
- Click Calculate — The tool displays the maximum vehicle price you can afford, your estimated monthly payment, total interest cost over the loan, and a flag if the purchase would push your total debt obligations above recommended thresholds.
How the Car Affordability Calculator Works
A car is the second-largest purchase most households make — and the one most likely to be made emotionally rather than financially. Dealership financing, monthly payment focus, and long loan terms make it easy to drive away in a vehicle that costs far more than your budget can comfortably support. This calculator anchors the decision in your actual financial picture so you know your number before you walk onto a lot.
The 15% Rule for Car Affordability
The most widely cited guideline for car affordability is that total vehicle expenses — monthly payment, insurance, fuel, and maintenance — should not exceed 15–20% of monthly take-home pay. For a household bringing home $5,000 per month, that’s a total car budget of $750–$1,000 per month across all vehicle-related costs, not just the loan payment. Insurance alone on a new vehicle can run $150–$300 per month depending on the driver profile and vehicle type, and fuel costs for an average driver add another $150–$250 per month. These costs need to be factored into the affordability calculation — not treated as separate from the car purchase decision.
Why Monthly Payment Focus Is a Trap
Dealerships and lenders frame car purchases around monthly payment because a low payment makes almost any vehicle seem affordable. Stretching a loan to 72 or 84 months reduces the monthly payment significantly — but it dramatically increases total interest paid, extends the period of negative equity, and ties you to a depreciating asset long past the point where repair costs begin rising. A $40,000 vehicle financed at 7% over 84 months has a monthly payment of roughly $595 — the same payment as a $28,000 vehicle financed over 48 months — but costs $10,000 more in total and leaves you owing more than the car is worth for most of the loan term. The monthly payment is not the cost of the car. The total purchase price plus total interest is the cost of the car.
Depreciation: The Hidden Cost of New Vehicles
New vehicles depreciate rapidly — typically losing 15–25% of their value in the first year and 40–50% within three years of purchase. This depreciation curve has two important financial implications. First, it means buyers of new vehicles are paying a significant premium for the experience of being the first owner, a premium that evaporates the moment they drive off the lot. Second, it creates negative equity risk: in the early years of a long auto loan, you may owe more on the vehicle than it’s worth, meaning if the car is totaled or you need to sell, you’d owe money out of pocket after the insurance payout or sale proceeds. Buying a two- to four-year-old used vehicle captures most of the new car depreciation without you being the one who paid for it.
Auto Loan Rates and Credit Score
Auto loan interest rates vary significantly based on credit score, lender, loan term, and whether the vehicle is new or used. As of mid-2025, average new car loan rates range from approximately 5% for borrowers with excellent credit (750+) to over 14% for borrowers with subprime credit (below 600). Used car loan rates are typically 1–2 percentage points higher than new car rates for the same credit profile. On a $30,000 loan over 60 months, the difference between a 5% rate and a 10% rate is approximately $80 per month and nearly $5,000 in total interest over the life of the loan. Improving your credit score before financing a vehicle — or securing financing through a credit union rather than dealer financing — can produce meaningful savings.
Dealer Financing vs. Outside Financing
Most buyers finance through the dealership because it’s convenient — but dealer financing is not always the best rate available. Dealerships work with a network of lenders and earn a markup on the interest rate they present to buyers, called the dealer reserve. A buyer who qualifies for a 6% rate may be offered 8% by the dealer, with the 2% spread going to the dealership as profit. The most effective protection against this is securing a pre-approved loan from your bank or credit union before visiting the dealership. With a competing offer in hand, you can either use your outside financing or challenge the dealer to beat it. Dealers frequently can and will match or beat outside rates to keep the financing in-house.
Total Cost of Ownership Over Five Years
The sticker price of a vehicle is only one component of what it will actually cost you to own over time. Total five-year ownership cost includes depreciation, financing charges, insurance premiums, fuel, maintenance and repairs, and registration fees. According to AAA’s annual Your Driving Costs study, the average total cost of owning and operating a new vehicle in 2024 was approximately $12,300 per year — or just over $1,000 per month — across all vehicle categories. SUVs and trucks run higher; small sedans and hybrids run lower. Understanding total cost of ownership, not just the monthly loan payment, is the foundation of a sound vehicle purchasing decision.
Auto Loan Payment Comparison by Vehicle Price and Term (2025)
The following table shows estimated monthly payments and total interest paid at a 7.0% APR across common vehicle prices and loan terms. A larger down payment of 10% of the vehicle price is assumed.
| Vehicle Price | 36 Months | 48 Months | 60 Months | 72 Months |
|---|---|---|---|---|
| $20,000 | $554/mo — $1,944 interest | $431/mo — $2,688 interest | $356/mo — $3,360 interest | $305/mo — $3,960 interest |
| $30,000 | $831/mo — $2,916 interest | $647/mo — $4,032 interest | $535/mo — $5,100 interest | $457/mo — $5,904 interest |
| $40,000 | $1,108/mo — $3,888 interest | $862/mo — $5,376 interest | $713/mo — $6,780 interest | $610/mo — $7,920 interest |
| $50,000 | $1,385/mo — $4,860 interest | $1,078/mo — $6,744 interest | $891/mo — $8,460 interest | $762/mo — $9,864 interest |
Assumes 10% down payment, 7.0% APR. Monthly payments and interest figures are rounded estimates for comparison purposes.
Frequently Asked Questions
How much should I spend on a car?
A conservative guideline is to keep the total vehicle purchase price — including all fees — below 35% of your gross annual income, with a monthly payment no higher than 10–15% of monthly take-home pay when combined with insurance. On a $60,000 annual salary, that suggests a vehicle price ceiling of roughly $21,000 and a combined payment-plus-insurance budget of $500–$750 per month. These guidelines feel restrictive compared to what lenders will approve, but they leave adequate room for retirement savings, emergency fund contributions, and other financial goals that compete for the same dollars.
Is it better to buy new or used?
From a pure financial standpoint, buying a certified pre-owned or used vehicle two to four years old is almost always the better value. New vehicles lose the largest chunk of their value in the first one to three years, meaning a used buyer captures the benefit of a mostly depreciated asset while still getting a vehicle with substantial remaining life. New vehicles carry higher insurance costs, higher registration fees in most states, and a premium simply for being new. The exception is when manufacturer incentives — zero percent financing, significant cash back — reduce the effective cost of new to near parity with used, or when a specific vehicle configuration isn’t available used in your market.
Should I pay cash or finance a car?
If you have the cash and the auto loan rate exceeds what you could reliably earn on that money — generally any rate above 4–5% — paying cash is the mathematically superior choice. It eliminates interest entirely and removes a monthly debt obligation. If your loan rate is below 4% — which was common during the low-rate era of 2020–2021 — investing the cash and carrying the low-rate loan may produce better long-term results. At current rates of 6–8% for most borrowers, paying cash is typically the better financial move if you can afford to without depleting emergency savings or retirement contributions.
What is a good interest rate for a car loan?
As of mid-2025, a good auto loan rate for a borrower with excellent credit (750+) is in the range of 5–6% for a new vehicle and 6–7% for a used vehicle. Borrowers with good credit (700–749) typically see rates of 6–8%. Anything above 10% is a signal to either delay the purchase while improving your credit score, make a larger down payment to reduce the loan amount, or seek financing from a credit union, which consistently offers more competitive rates than banks or dealer financing for borrowers across the credit spectrum.
How long should my car loan be?
The shortest term you can comfortably afford is almost always the best financial choice. A 36- or 48-month loan minimizes total interest paid and reduces the period of negative equity — the stretch where you owe more than the car is worth. The popularity of 72- and 84-month loans is a product of rising vehicle prices and the industry’s success at shifting buyer focus from total cost to monthly payment. If you need a 72- or 84-month loan to make the payment affordable, that’s a strong signal the vehicle is priced beyond what your budget can support — and the solution is a less expensive vehicle, not a longer loan term.
What is gap insurance and do I need it?
GAP insurance — Guaranteed Asset Protection — covers the difference between what you owe on an auto loan and what the vehicle is worth if it’s totaled or stolen. Because new vehicles depreciate faster than loan balances shrink in the early years of financing, many borrowers are underwater — owing more than the car is worth — for the first two to three years of a long loan. Standard auto insurance only pays the vehicle’s actual cash value at the time of loss, not the remaining loan balance. If you finance more than 80% of a new vehicle’s value, GAP insurance is worth considering. It’s typically far cheaper when purchased through your auto insurer than through the dealership.
Tips for Making a Sound Car Buying Decision
- Get pre-approved before visiting a dealership. Walking into a dealership without financing in place puts the dealer in control of a critical variable. Secure a pre-approval from your bank or credit union first — it takes 15–30 minutes online and gives you a rate benchmark the dealer must compete with. Pre-approval also clarifies your actual budget ceiling before you start test driving vehicles, reducing the risk of falling in love with something outside your range.
- Negotiate the purchase price separately from the monthly payment. Dealers prefer to negotiate around monthly payment because it obscures the total cost of the vehicle. Insist on agreeing to the out-the-door purchase price — the total amount you’re paying for the vehicle including all fees and add-ons — before any discussion of financing terms. Once the price is locked, financing is a separate conversation. Mixing the two allows dealers to give you a lower payment while quietly increasing the total cost through loan term extension or add-on products.
- Research the vehicle’s total cost of ownership before buying. Use resources like Edmunds True Cost to Own or Consumer Reports reliability data to understand the full five-year cost picture for any vehicle you’re seriously considering. Two vehicles at the same purchase price can have dramatically different insurance costs, fuel costs, maintenance schedules, and reliability records. A vehicle that costs $2,000 more to buy but $1,500 less per year to own over five years is the better financial choice — a calculation that’s easy to miss if you focus only on sticker price.
- Avoid adding products at the finance desk. After agreeing on a purchase price, buyers are typically taken to a finance and insurance (F&I) office where a menu of add-on products is presented: extended warranties, paint protection, fabric protection, tire and wheel protection, and others. These products are high-margin items for the dealership and are almost always available for significantly less through independent providers or not worth their cost at all. Politely decline everything at the F&I desk and research any product you’re genuinely interested in independently before your next visit.
- Time your purchase strategically. Vehicle pricing is not static — dealers and manufacturers run incentive programs that make certain times of year consistently better for buyers. End of month, end of quarter, and end of model year (typically late summer to early fall when new model year inventory arrives) are periods when dealers are more motivated to move units and more willing to negotiate. Holiday weekend sales events — Memorial Day, Labor Day, Presidents’ Day — also frequently feature manufacturer incentives that reduce effective purchase price for qualified buyers.