"What can I afford?" is the most important question in car shopping, and it's worth answering before you fall in love with a car on the lot. This guide gives you a simple way to find a number that fits your life, not just your loan approval.
Start with your monthly take-home pay
Use your take-home pay, the amount that actually lands in your bank account, not your gross salary. That's the money you'll be paying the car with.
The 10–15% rule of thumb
A common guideline is to keep your total monthly car costs at about 10% to 15% of your take-home pay. "Total" is the key word. It includes:
- Your loan payment
- Car insurance
- Fuel
- Routine maintenance and repairs
- Parking, tolls, or other regular costs
If you take home $3,500 a month, 10–15% is roughly $350 to $525 a month for everything car-related. If insurance and gas run you $250, that leaves about $100 to $275 for the payment.
Estimate your real ownership costs
Insurance
Get a quote before you buy. Insurance can vary widely by vehicle, your driving record, age, and ZIP code. A sporty car or a luxury model can cost much more to insure than a practical sedan.
Fuel
Estimate your weekly miles and divide by the car's combined MPG to get gallons per week, then multiply by local gas prices. The difference between 22 and 32 MPG adds up fast if you commute.
Maintenance and repairs
Older and higher-mileage cars generally need more upkeep. Budget for oil changes, tires, brakes, and an emergency cushion. Setting aside a little each month means a repair bill doesn't become a crisis.
Then think about total price, not just the payment
It's easy to make almost any car look affordable by stretching the loan longer. But a longer loan usually means:
- More total interest paid
- A higher chance of owing more than the car is worth
- Payments that continue long after the new-car feeling wears off
Here's how the math works on a $15,000 loan. These are illustrations, not quotes; your actual rate depends on your credit and lender.
| Loan term (illustration: $15,000 at 9%) | Monthly payment | Total interest |
|---|---|---|
| 48 months | About $373 | About $2,900 |
| 72 months | About $270 | About $4,500 |
The 72-month loan has a lower payment, but costs roughly $1,550 more over its life.
A longer term can still be a smart choice
A longer term isn't a trap if you use it wisely. It gives you a lower, more comfortable payment and breathing room in your monthly budget, and you're not locked into paying all of that interest. Most auto loans charge interest on the balance you still owe, so:
- Pay extra when you can. Extra payments, or paying the loan off early, cut down the interest you pay. Ask your lender to apply extra payments to the principal.
- Trade in or sell before the term ends. When you trade in the car, the remaining balance is paid off as part of the deal, and you stop paying interest on it from that point on.
That way you get the lower payment now, and the flexibility to pay less interest later, with no extra fees for paying the loan off early.
How a down payment helps
Money down reduces the amount you borrow, which lowers your payment and total interest. It can also help with approval if your credit is still being rebuilt. A trade-in counts too. You can get an offer on your current car to see how much it could put toward your next one.
Don't forget taxes and fees
The sticker price isn't the out-the-door price. In Illinois, plan for:
- Sales tax (state plus local, depending on where you live)
- Title and registration fees
- The dealer documentation fee (Illinois sets a yearly maximum)
Our guide to Illinois used car taxes and fees breaks these down.
A quick worksheet
- Monthly take-home pay: ______
- Multiply by 0.10 to 0.15 for your total car budget: ______
- Subtract estimated insurance: ______
- Subtract estimated fuel: ______
- Subtract a maintenance set-aside: ______
- What's left is your comfortable payment: ______
Bring that number with you as a starting point, and keep a little flexibility. Lenders decide approval based on your credit, income, the vehicle, and the loan term, so sometimes the approval that works is a few dollars a month above your target. Stretching slightly, or choosing a longer term, can be what gets you approved and into a reliable car. Remember, you can always pay the loan off early or trade the car in later to cut down the interest.
Not sure what fits? Let us help
Tell us your budget and what you need in a car, and our team will match you with options, even if the right car isn't on our lot yet. Try our Car Finder or apply for financing to see where you stand.