In July 2022, it was roughly $4.52 for a gallon of gas. That's according to the AAA, as quoted by RocketHQ. It can depend on the size of your car's engine and to how many gallons it takes to fill it up. A bigger car that can hold 16 gallons would be approximately $57 to fill up. A smaller car holding 12 gallons will cost around $46 to fill up with gas. The costs for you to fill up will vary depending on different factors. For example, it depends on how often you use the car, how many miles you drive a week or month, how much weight your car has to carry, how cost-effective your driving is, the price per gallon, and so on.