Car Affordability Calculator
Find your maximum car price using the 20/3/8 affordability rule.
This tool is for informational and educational purposes only. It is not a substitute for professional financial, medical, legal, or engineering advice. See Terms of Service.
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This calculator tells you the maximum car price you can comfortably afford based on your income and expenses. It uses the 20/3/8 rule, a conservative guideline that keeps car costs from eating into your budget.
- Enter your gross monthly income. This is your total income before taxes and deductions. If you are paid biweekly, multiply your paycheck by 26 and divide by 12.
- Set your down payment percentage. The 20/3/8 rule recommends at least 20% down. A larger down payment reduces your loan and monthly payment.
- Choose a loan term. The rule recommends 36 months or shorter. Shorter terms mean less interest paid overall, even though monthly payments are higher.
- Enter the interest rate. Check your bank or credit union for pre-approved rates. The rate you qualify for depends on your credit score.
- Add insurance and gas estimates. These are included because the 8% rule covers all vehicle-related expenses, not just the loan payment.
About the 20/3/8 Rule
The 20/3/8 rule is a car affordability guideline with three parts. First, put at least 20% down to avoid being underwater on the loan. Second, keep the loan term to 3 years (36 months) or less to minimize interest and avoid paying for a depreciating asset longer than necessary. Third, total monthly vehicle expenses (loan payment, insurance, and fuel) should not exceed 8% of your gross monthly income. This rule is more conservative than the older 20/4/10 rule and helps prevent buyers from stretching their budget on a car that costs more than they can realistically handle.
Frequently Asked Questions
What is the 20/3/8 rule for buying a car?
The 20/3/8 rule says you should put at least 20% down on a car, finance it for no more than 3 years (36 months), and keep total vehicle expenses (payment, insurance, gas) under 8% of your gross monthly income. It is a stricter version of the 20/4/10 rule and helps prevent overspending on a vehicle.
How much car can I afford on a $5,000 monthly income?
With $5,000 gross monthly income, 8% gives you $400/month for all car expenses. After subtracting typical insurance ($150) and gas ($100), you have $150/month for the car payment. At 6.5% APR for 36 months, that supports a loan of about $4,880, which means a maximum car price around $6,100 with 20% down. If your insurance and gas costs are lower, you can afford more.
Is the 20/3/8 rule too strict?
The 20/3/8 rule is intentionally conservative. Most Americans spend far more than 8% of income on their car. If you have no other debt, a fully funded emergency fund, and are saving at least 15% for retirement, you may be able to stretch to 10% of income. However, the 8% target keeps transportation costs manageable and leaves room for other financial goals.
Does this calculator include insurance and gas?
Yes. The 8% limit applies to your total vehicle expenses, not just the loan payment. Enter your estimated monthly insurance and gas costs, and the calculator subtracts them before determining how much loan payment you can afford. This gives you a realistic picture of what you can actually spend on the car itself.