Car Affordability Calculator
Find out how much car you can afford based on your monthly income, existing debts, down payment, and loan terms.
Formulas, assumptions, and rounding are documented in our calculator methodology.
Loan Term
Estimated Affordable Vehicle Price
$37,674.19
15% of monthly income rule
Monthly Cost Breakdown
- Estimated Loan Payment
- $750.00
- Insurance
- $150.00
- Fuel & Maintenance
- $200.00
- Total Monthly Car Cost
- $1,100.00
- Payment-to-Income
- 15.0%
- Total Cost-to-Income
- 22.0%
Loan Summary
- Amount Financed
- $37,876.50
- Total Interest
- $7,123.50
- Total Loan Cost
- $45,000.00
The 15% Rule for Car Buying
Financial experts often recommend keeping your monthly car payment at or below 15% of your gross monthly income. If you earn $5,000/month, that means a maximum payment of $750. This calculator uses this guideline unless you specify a custom budget.
Total Cost of Car Ownership
Your car payment is just one expense. Budget for insurance (often $100–250/month), fuel ($100–200+/month), maintenance and repairs ($80–150/month average), and depreciation. The total monthly cost of ownership is often 1.5–2× the loan payment alone.
Safe, Comfortable, and Aggressive Car Budgets
There is no single right answer — context matters. Safe budget: monthly payment ≤ 10% of gross income, 48-month term, 20% down. Comfortable budget: payment ≤ 15% of gross income, 60-month term, 10% down. Aggressive budget: payment up to 20% of gross income, 72-month term, minimal down. Income example ($6,000/month gross): Safe = up to $600/mo (≈$27,000 vehicle at 6%, 48mo, 20% down). Comfortable = up to $900/mo (≈$46,000 vehicle at 6%, 60mo, 10% down). The aggressive budget increases ownership risk significantly. If you are buying your first car or have limited savings, the safe budget provides the most cushion.
New vs. Used Car Affordability
New cars offer manufacturer warranties, the latest safety features, and financing rates 1–3% lower than used cars — but they depreciate 15–25% in the first year alone. A $35,000 new car may be worth $27,000 after one year. Certified pre-owned (CPO) vehicles 2–4 years old offer a middle ground: depreciation already absorbed, manufacturer-backed warranty, and lower purchase price. For buyers on a tighter budget, a reliable 3–5-year-old used vehicle purchased outright or with a short loan term maximizes value and minimizes financial risk. When comparing new vs. used, factor in total interest paid over the life of each loan, not just the monthly payment difference.
Frequently Asked Questions
- A common guideline is to keep your monthly car payment under 15% of your gross monthly income. Total car costs (payment + insurance + fuel/maintenance) should ideally stay under 20% of income.
- Yes. A down payment of 10–20% reduces your loan amount, lowers monthly payments, reduces total interest paid, and helps you avoid being underwater on the loan (owing more than the car is worth).
- Trade-in value is applied directly to reduce the amount you need to finance, similar to a down payment. This lowers your monthly payment and total interest paid.
- A 72-month term lowers monthly payments but significantly increases total interest paid. Cars also depreciate quickly, so a long loan increases the risk of being underwater. Aim for 48–60 months when possible.
- The 20/4/10 rule is a popular car-buying guideline: put at least 20% down, finance for no more than 4 years, and keep total monthly car expenses (payment + insurance) under 10% of gross monthly income. It is a conservative benchmark designed to prevent buyers from overextending on a depreciating asset. Many buyers cannot meet all three criteria simultaneously, so treat it as a goal rather than a hard rule — but violating all three at once is a strong signal the car is unaffordable.
- Lenders use debt-to-income (DTI) ratio to assess risk. Most lenders cap total monthly debt (including your new car payment) at 43% of gross monthly income. If you earn $5,000/month and already pay $1,200/month in debts, you have roughly $950 left under the 43% cap before insurance and fuel — limiting your car payment significantly. The calculator automatically applies this constraint when your existing debts are high.
- National average auto insurance is roughly $150–200/month for full coverage, though rates vary widely by state, age, driving record, vehicle type, and coverage level. Lenders typically require full coverage (collision + comprehensive) on financed vehicles. Young drivers and those in high-rate states like Michigan, Florida, or Louisiana can expect premiums well above average. Always get an insurance quote before finalizing your vehicle budget.
- Beyond the monthly loan payment, owning a car typically costs: auto insurance ($150–250/month for full coverage), fuel ($100–200/month for most drivers), routine maintenance ($80–150/month averaged over the vehicle's life — oil changes, tires, brakes, filters), and unexpected repairs (budget extra as the vehicle ages). Registration and licensing fees add $20–50/month on average. Total ownership costs are typically 1.5–2× the loan payment alone.