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How Much Car Can You Afford?

The 20/4/10 rule, why total cost matters more than the monthly payment, and how to set a car budget that won’t wreck the rest of your finances.

By David MilesAugust 9, 20262 min read

The short version

  • A common guideline is 20/4/10: 20% down, a loan no longer than 4 years, and all car costs under 10% of gross income.
  • Budget for total cost of ownership — insurance, gas, maintenance, and registration — not just the loan payment.
  • The average new-car payment is now around $770 a month; that doesn’t mean you should aim for it.
  • Stretching the loan term to hit a lower payment is a warning sign you’re buying too much car.

At the dealership, the question is always “what monthly payment works for you?” That’s the wrong question. A payment you can technically make can still be a car you can’t really afford once insurance, gas, and repairs pile on — or once it eats the money that should go to savings and debt. Here’s how to set a car budget that holds up.

The 20/4/10 rule

A simple, battle-tested guideline keeps three numbers in check at once:

  • 20% down — put at least a fifth of the price down to avoid owing more than the car is worth.
  • 4-year loan — finance for no more than 48 months; if you need longer to afford it, it’s too expensive.
  • 10% of income — keep all car costs (payment, insurance, fuel, upkeep) under 10% of your gross income.

On a $60,000 income, the 10% ceiling is about $500 a month for everything car-related — not $500 for the payment plus more on top. It’s a ceiling, not a target.

The payment isn’t the cost

The loan payment is only the visible part of owning a car. Every month you’re also paying for insurance, fuel, maintenance, and — spread out — registration, tires, and repairs. Two cars with the same payment can cost hundreds of dollars a month apart once you count all of it. Before you fall for a sticker price, add up the total cost of ownership.

Average doesn’t mean affordable

The average new-car payment recently topped $770 a month, and used cars average around $530. Those are what people are paying — not what’s wise. Anchoring to the average is how car costs quietly crowd out saving and investing.

Watch the loan term

If the only way to reach a comfortable payment is a 72- or 84-month loan, that’s the clearest signal you’re reaching for too much car. Longer terms shrink the monthly number but pile on interest and keep you “underwater” — owing more than the car is worth — for years. The affordability math should work at four years, not seven.

Set your number

Enter your income, down payment, and rate to see the car price and payment that actually fit your budget.

Once you have a price in mind, check the monthly payment and total interest at different loan terms before you sign.

Sources

This article is for general education and is not financial, tax, or legal advice. Figures reflect published 2026 IRS and SSA amounts as of the date above; verify current limits with the linked sources or a qualified professional before acting.

About the author

David Miles is the founder of FigureMoney and builds independent, source-backed personal-finance tools across the Modern Site Builders network. Every calculator and guide cites the IRS, SSA, or primary research behind its numbers.