Car Buying & Auto Loan FAQ

The 20/4/10 rule is a good starting point: 20% down, 4-year loan maximum, and car payment under 10% of your gross monthly income. For a more precise estimate, use our Car Affordability Calculator which factors in your state's sales tax, insurance rates, and loan terms.

The 20/4/10 rule helps you avoid overpaying: put 20% down, finance for no more than 4 years (48 months), and keep total car costs (payment + insurance) under 10% of your monthly income. This keeps your auto budget healthy and avoids being upside-down on your loan.

Yes! Sales tax can add $1,000–$3,500 to a $35,000 car depending on your state. Our calculator automatically includes your state's sales tax rate in the affordability estimate. States like Alaska, Delaware, Montana, New Hampshire, and Oregon have 0% state sales tax, while California can reach over 10% with local taxes.

With $60,000/year ($5,000/month), the 10% rule suggests a max car payment of $500/month. At current rates (7%), that's roughly a $25,000–$28,000 car loan. With 20% down, your total car budget would be around $31,000–$35,000. Use our calculator for a personalized estimate based on your actual income and expenses.

Ideally 720+ for the best rates (5–7%). With 650–719, expect 8–12% rates. Below 650, you may face 15%+ or need a co-signer. Check your score free at AnnualCreditReport.com before visiting dealers.

Yes! Getting pre-approved at your bank or credit union before visiting dealers gives you: (1) a clear budget, (2) bargaining power ("I have financing at X%"), and (3) protection from dealer markup. Dealers often add 1–2% to your rate as commission — pre-approval helps you avoid this.

Refnancing makes sense if: (1) your credit score improved 50+ points, (2) market rates dropped 1–2%+, (3) you want to lower your monthly payment. Use our Auto Refnance Calculator to see if the savings outweigh the costs. A break-even under 12 months is ideal.

In 2026, excellent credit (720+) can get 5.5–7.5% for new cars and 7–9% for used cars. Good credit (650–719) typically sees 9–13%. Rates vary by lender — banks, credit unions, and captive finance companies (Toyota Financial, Honda Financial, etc.) offer different rates. Always get quotes from at least 3 lenders.

Lease if you: drive under 12,000 miles/year, want lower monthly payments, and prefer driving a new car every 2–3 years. Buy if you: drive a lot, want to build equity, or plan to keep the car 5+ years. Use our Lease vs Buy Calculator to compare total costs.

New cars depreciate 20% in year 1 but have full warranties. Used cars (2–4 years old) have already taken the biggest depreciation hit and offer better value. Use our New vs Used Comparison to calculate which is cheaper for your situation.

You need gap insurance if: (1) you put less than 20% down, (2) you financed for 60+ months, or (3) you bought a new car (depreciates fast). Gap covers the difference between your car's value and loan balance if it's totaled. Always buy it from your auto insurer ($5–$15/year) — not the dealer ($500–$700 upfront).

Alaska, Delaware, Montana, New Hampshire, and Oregon have no state sales tax. However, consider the total cost: registration fees, insurance rates, and local taxes also vary by state. Our State Guides show the full cost breakdown for all 50 states.

Yes! All CarAffordCalc.com calculators are 100% free. No registration, no email required. All calculations run in your browser — we don't collect or store any personal information. You can use our tools as many times as you want.

Our calculators use standard industry formulas and current 2026 data (state sales tax rates, average insurance costs, typical loan rates by credit score). However, your actual rates depend on your specific lender, credit profile, and dealer fees. Always get final numbers from your lender before signing. Read our full disclaimer.

Yes! Each calculator has a Save Scenario button (💾 icon) that saves your inputs to your browser's local storage. You can return later and your numbers will still be there. For sharing, use the Share button (🔗 icon) to copy the page URL with your inputs pre-filled.