Free car budget tool
Car Affordability Calculator — How Much Car Can You Afford?
Enter your income, debts and down payment to find your safe car budget — checked against the 20/4/10 rule and the 15% income guideline.
Find Your Car Budget
Adjust any value — results update instantly.
20/4/10 Rule Check
How Much Car Can You Afford?
A car you can afford is one where the total monthly cost — payment, insurance, fuel and maintenance — fits comfortably in your budget without crowding out savings or other debts. Two widely used guidelines help you draw that line:
The 20/4/10 Rule
- 20% down payment (including trade-in) — protects you from going underwater.
- 4-year loan term or shorter — keeps total interest low (5 years is a common compromise).
- 10% of gross income on total car costs — the conservative ceiling many advisors use.
The 15% Income Guideline
Many financial planners allow up to 15% of gross monthly income for all transportation costs. The calculator above shows your max payment at 15% and flags anything above it.
Don’t Forget the Hidden Costs
The monthly payment is only part of ownership. Budget roughly $100–$200/month for insurance, $80–$150 for fuel (gas car, average driving), and $50–$100 for maintenance and repairs. The “total monthly car cost” line above includes conservative estimates for these.
Once you know the price range you can afford, use our auto loan calculator to see the exact monthly payment and total interest for that amount.
Frequently Asked Questions
What is the 20/4/10 rule for buying a car?
Put 20% down, finance for no more than 4 years, and keep total monthly car expenses under 10% of your gross income. It’s a conservative rule that keeps you from overextending.
What percentage of my income should go to a car?
Most advisors say 10–15% of gross monthly income for all car costs (payment, insurance, fuel, maintenance). Above 20% is generally considered unaffordable.
How does debt-to-income ratio affect car affordability?
Lenders look at your DTI — total monthly debts divided by gross income. Under 36% is ideal; above 43% makes approval harder and the payment riskier for you.
Is a bigger down payment always better?
Generally yes — 20% avoids being underwater and lowers your payment and interest. But don’t drain your emergency fund to do it; keep 3–6 months of expenses saved.
Should I include trade-in in my down payment?
Yes — trade-in equity counts toward the 20% down target and reduces your amount financed exactly like cash down.
What if I can afford the payment but not the 20% down?
Consider a cheaper car, waiting and saving, or a larger trade-in. Small down payments mean higher payments, more interest, and risk of owing more than the car’s worth.
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