How do I figure out how much car I can afford?

A practical starting point is the 15% rule: your total monthly vehicle cost (payment plus insurance plus fuel plus estimated maintenance) should not exceed 15% of your monthly take-home pay. So on a $6,000 monthly net income, your total car budget is around $900 per month. If your payment is $450, insurance is $200, and fuel and maintenance average $150, you are at $800 and within a healthy range. This is more conservative than the 20% rule some financial advisors use, but leaves more flexibility for other financial goals. The number that matters most is total cost, not just the monthly payment.