Auto Loan Calculator: What Car Can You Actually Afford?

Published August 2026 | 6 min read

The average new car payment in the U.S. is now $726/month. For used cars, it's $526. Before you step onto a dealer lot, you need to know your real budget — not the one the salesperson wants you to have.

Use our free auto loan calculator to find your payment, total interest, and whether that car fits your budget.

The 20/4/10 Rule for Car Buying

This simple rule keeps you from overspending:

20% down — Prevents negative equity and reduces monthly payment
4-year max loan — Longer loans = more interest + risk of being upside-down
10% of gross income — Total monthly car costs (payment + insurance + gas) shouldn't exceed this

On a $60,000 salary, that's $500/month max for everything car-related. If insurance is $150 and gas is $100, your loan payment should be under $250.

New vs. Used: The Real Cost Difference

A $30,000 new car vs. a $15,000 used car, both at 6% APR for 48 months:

	New Car	Used Car
Monthly Payment	$705	$352
Total Interest	$3,818	$1,909
Value in 4 Years	~$15,000	~$8,000
Total Depreciation	$18,818	$8,909

The used car costs $10,000 less in total depreciation. That's a year of retirement contributions.

How to Get the Best Auto Loan Rate

Check your credit first — Know your score before dealers run it. Use a free service.
Get pre-approved — Credit unions and online lenders often beat dealer rates by 1–3%.
Keep the loan under 48 months — 72-84 month loans have higher rates and trap you in negative equity.
Put 20% down minimum — Protects against depreciation and gets you better rates.
Skip the extras — Extended warranties, gap insurance, and paint protection are dealer profit centers.

The Hidden Cost: Depreciation

New cars lose 20% in year one, then 15% per year after. A $35,000 car is worth:

After 1 year: $28,000 (-20%)
After 3 years: $20,200 (-42%)
After 5 years: $12,400 (-65%)

This is why 3–5 year old used cars are the sweet spot — someone else ate the depreciation.

💡 Compare Auto Loan Rates

Get pre-approved before you shop. See rates from multiple lenders in minutes.

Check Auto Loan Rates →

The Bottom Line

A car is a tool to get you places, not a status symbol. Use our auto loan calculator to find a payment that fits the 20/4/10 rule, then shop used cars in the 3–5 year range. Your future self will thank you.