Budget before you browse
How much car can you actually afford?
Three answers in one place: your income-based budget with the 20/4/10 rule, your monthly payment at real 2026 used-car interest rates for your credit tier, and what the car will truly cost each month once insurance, gas, and maintenance join the party.
Last updated: July 2026 · Free · No signup
Your numbers
Income = before taxes. Include your whole household if you share the bills.
Credit tier (sets the APR)
APRs preset to Experian Q1 2026 used-car averages — replace with your own quote if you have one.
What counts toward the 10%?
Running costs per month
Defaults: $244/mo average full-coverage insurance (Experian, May 2026), $3.82/gal gas (AAA), 11¢/mi maintenance (AAA).
Planning estimate, not financial advice. Taxes, title, and registration fees vary by state and are not included.
Your car budget
Max car price (loan + down payment)
$9,441
- 10% of gross income
- $650.00/mo
- Insurance
- −$244.00
- Gas (1,000 mi)
- −$136.43
- Maintenance & tires
- −$110.00
- Room for a loan payment
- $159.57/mo
- Max loan (8.77% APR, 48 mo)
- $6,441
- Down payment share of max price
- 32%
Context: the average used-car loan in Q1 2026 was $27,070 at 11.43% APR for 68 months — a $531/mo payment (Experian).
Solid — this budget follows the full 20/4/10 rule
Payment, insurance, gas, and upkeep all fit within 10% of your income with at least 20% down. Shopping below your max price buys you an extra safety margin.
The 20/4/10 rule, explained
The 20/4/10 rule is the classic car-budget guardrail: put at least 20% down, finance for no more than 4 years, and keep all transportation costs — payment, insurance, gas, and upkeep — at or under 10% of your gross monthly income. Each number attacks a different way car deals go wrong: the down payment keeps you from owing more than the car is worth, the short term caps the interest, and the 10% ceiling protects the rest of your life from the car.
Fair warning: the strict version has gotten hard. Financial planners note that with today’s prices and rates, few buyers hit all three numbers — the average used-car loan now runs $27,070 over roughly 68 months. That is not a reason to ignore the rule; it is a reason to shop the used market, where the rule still works. The calculator above lets you toggle between the strict rule and a payment-only version so you can see both realities.
Average used-car loan rates by credit score (Q1 2026)
Your credit tier is the single biggest lever on what a used car costs to finance. The overall used-car average was 11.43% APR with a $531 monthly payment:
| Credit tier | Score range | Used car APR | New car APR |
|---|---|---|---|
| Super prime | 781–850 | 6.30% | 4.55% |
| Prime | 661–780 | 8.77% | 6.23% |
| Near prime | 601–660 | 14.03% | 9.67% |
| Subprime | 501–600 | 19.42% | 13.44% |
| Deep subprime | 300–500 | 21.77% | 16.01% |
Source: Experian — State of the Automotive Finance Market, Q1 2026
Worked example: $80,000 household, strict 20/4/10
A household grossing $80,000 a year has $3,500 saved for a down payment, prime credit (8.77% APR average), and drives 1,000 miles a month. Here is the strict rule, line by line:
| Line | Amount |
|---|---|
| Gross income per month | $6,666.67 |
| 10% all-in transport budget | $666.67 |
| Insurance (national full-coverage average, $244/mo) | −$244.00 |
| Gas: 1,000 mi ÷ 28 MPG × $3.82/gal | −$136.43 |
| Maintenance & tires: 1,000 mi × 11¢ | −$110.00 |
| Room left for a loan payment | $176.24 |
| Max loan at 8.77% over 48 months | $7,113 |
| Max car price with $3,500 down | ≈ $10,613 |
Sobering, right? The relaxed payment-only version of the rule stretches the same household to roughly a $30,400 car on a loan of about $26,900 — almost exactly the national average loan, which is precisely why so many buyers feel stretched. The used market is where the honest math still works: a well-kept $8,000–$12,000 private-party car fits the strict rule with room to spare. When you find one, close the deal properly with a free bill of sale.
Frequently asked questions
What credit score do I need to finance a used car?
There is no single minimum — lenders approve borrowers across the whole range, but the price of the money changes drastically. In Q1 2026, used-car buyers with super prime credit (781+) averaged 6.30% APR while deep subprime borrowers (300–500) averaged 21.77% (Experian). On a $12,000 loan over 60 months, that spread is roughly $5,800 of extra interest for the same car.
Is the 20/4/10 rule still realistic in 2026?
The strict version is genuinely hard now: the average used-car loan is $27,070 over roughly 68 months — a longer term than the rule allows on a bigger loan than most budgets support. Treat 20/4/10 as a target that protects you, not a law. This calculator shows both the strict version (payment plus insurance, gas, and upkeep within 10% of income) and the relaxed payment-only version most people actually use.
Is it cheaper to buy from a private seller than a dealer?
Usually, yes — private-party prices skip the dealer margin, reconditioning markup, and add-on fees. The trade-offs: no warranty, and financing takes one extra step, since you arrange a private-party auto loan through your bank or credit union instead of signing at a dealer desk. Always verify the title matches the seller and put the deal in writing with a bill of sale.
How much should I put down on a used car?
The classic guideline is 20% of the price — enough to absorb first-year depreciation so you never owe more than the car is worth. At minimum, put down enough to cover taxes and fees plus a cushion. Every extra dollar down also shrinks the interest: a $12,000 loan at the prime used-car average of 8.77% over 60 months costs about $2,866 in interest; the same loan at the subprime average of 19.42% costs about $6,844.
What does owning a car really cost per month?
The payment is only the start. Add full-coverage insurance (a $244/month national average in 2026, per Experian), gas (AAA national average $3.82/gallon as of early July 2026), and maintenance, repairs, and tires (about 11¢ per mile, per AAA). Registration, property taxes, and parking vary by state and city. As a benchmark, the IRS puts the all-in cost of driving at 76¢ per mile for the second half of 2026 — raised mid-year from 72.5¢ because of rising fuel prices.
This page is general information, not financial advice. Rates shown are market averages — your quote will differ. Confirm loan terms with your lender.
Next step
Now go find the car
Private-party used cars on Brixaz skip the dealer markup — the same budget buys more car. Browse listings near you, and when you close the deal, our free bill of sale has both of you covered. Selling first to fund the upgrade? Post your car free: $0 fees, no commissions.