Turn your monthly payment budget into a maximum sticker price, tax and fees included
| Monthly Budget | Max Sticker Price | Amount Financed | Total Interest |
|---|---|---|---|
| $300 | $16,652 | $15,151 | $2,849 |
| $400 | $21,416 | $20,201 | $3,799 |
| $500 | $26,180 | $25,251 | $4,749 |
| $600 | $30,945 | $30,301 | $5,699 |
| $700 | $35,709 | $35,351 | $6,649 |
Assumes $4,000 down, 6% sales tax, and $1,500 in fees. Longer terms buy more sticker for the same payment, but interest grows fast: the $700 row on a 72-month loan finances about $41,100 instead of $35,400.
| Credit Score | Typical New-Car APR | Typical Used-Car APR | Payment on $20,000 / 60 mo (new) |
|---|---|---|---|
| 781+ (super prime) | ~5% – 6% | ~6% – 7% | $377 – $387 |
| 720 – 780 | ~6% – 8% | ~7% – 9% | $387 – $406 |
| 661 – 719 | ~9% – 11% | ~10% – 13% | $415 – $435 |
| 601 – 660 | ~12% – 14% | ~14% – 17% | $445 – $465 |
| 300 – 600 | ~16% – 19% | ~18% – 21% | $486 – $519 |
Bands reflect typical national average ranges; your quote depends on lender, loan-to-value, and the vehicle. A credit union pre-approval is the fastest way to know your real number before a dealer marks it up.
Most car payment calculators run the easy direction: pick a car, get a payment. This one runs backwards, because that's how budgets actually work. You know what you can pay each month. The calculator figures out the highest sticker price that payment supports once sales tax, dealer fees, and your down payment are all accounted for.
First, the payment-to-loan step. A monthly payment M at monthly rate r for n months supports a loan of L = M × (1 − (1 + r)−n) ÷ r. Then the loan-to-sticker step: out-the-door price = loan + down payment, and out-the-door = sticker × (1 + sales tax) + fees. Solving for sticker gives (L + down − fees) ÷ (1 + tax rate).
Enter the payment you can genuinely afford each month, not the one a lender approves. Lenders will often stretch a car payment to 20% or more of gross income, which is how buyers end up car-poor. Add your down payment and trade-in together in one field. Sales tax defaults to 6%; check your state's rate, since in most states it's charged on the price before the down payment comes off. Fees cover documentation, title, and registration, which commonly run $1,000 to $2,000 combined.
Say you can put $450 a month toward a car, you have $4,000 saved, and you're looking at a 60-month loan at 7.2% APR in a state with 6% sales tax and $1,500 in fees. The annuity factor at 7.2% for 60 months is 50.2621, so $450 supports a loan of $450 × 50.2621 = $22,618. Add the $4,000 down and subtract the $1,500 in fees, then divide by 1.06: $25,118 ÷ 1.06 = a maximum sticker of about $23,696. The out-the-door total is $26,618, and over the loan you'll pay $4,382 in interest, bringing the all-in cost to $31,000.
Notice what the tax did. Without it, that $450 payment with $4,000 down and $1,500 of fees would buy about $25,118 of car. The 6% tax shaves the sticker to $23,696, roughly $1,400 less car for the identical payment. Shop in a no-sales-tax state like Oregon or Montana and you get that money back.
At 7% APR on a 60-month loan with $4,000 down, 6% sales tax, and $1,500 in fees, a $500 payment supports about a $26,180 sticker price. Stretch to 72 months and the number climbs toward $30,000, but you'll pay more interest and stay upside down longer. A $60,000 salary also puts $500 at the 10% ceiling of the 20/4/10 rule.
Put at least 20% down, finance for no more than 4 years, and keep total transportation costs under 10% of your gross income. On a $60,000 salary that means $500 a month for the payment, insurance, and fuel combined, which shrinks what you can finance once insurance runs $150 to $250 a month.
Sales tax is charged on the vehicle price before your down payment is subtracted in most states, so a 6% rate effectively cuts your buying power by about 6%. On a $25,000 budget that's roughly $1,500 of sticker price. Oregon, Delaware, Montana, and New Hampshire charge no state sales tax at all, which stretches the same payment further.
Both raise your effective buying power per dollar, but they work differently. A shorter term slashes total interest but forces a higher payment for the same car. A bigger down payment reduces the loan directly, which means less interest and a smaller gap to close if you sell early. If you must pick one, the shorter term is the safer habit; the bigger down payment is the faster lever.
National average rates by credit band run roughly 5% to 6% for scores above 780, 6% to 8% around 720 to 780, 9% to 11% around 660 to 719, 12% to 14% around 600 to 659, and 16% to 19% below that. Used-car rates sit 1 to 3 points above new-car rates in every band. Always check a bank or credit union quote before accepting dealer financing.