The answer to this question is not that straightforward because it all depends on the car that you're driving. A smaller car will obviously get more miles per gallon than a larger SUV. However, there are other factors to consider as well such as the type of terrain that you're driving on and your driving habits. If you're someone who likes to push the pedal to the floor then you can expect to burn through gas much quicker than someone who takes it easy on the roads. To give you a general idea, a full tank of gas in an average vehicle will last anywhere from 200 to 400 miles. Of course, this number will be higher or lower depending on the factors that we mentioned earlier. But it's always good to know approximately how long you can expect your full tank of gas to last you. Also, you can search online on how long your vehicle's make and model can last on a full tank.