How much should an 13 year old charge for babysitting?

It depends on the amount of kids you are watching, and how long you will be babysitting. In my point of view, if you were babysitting one child, charge about $3+.
So if you were babysitting five children, you would simply times your price of one child with the number of children you are tending. Confused? Here's some examples: say you were watching five children for three hours. The total profit would come to about $45, but that seems a little pricy to you, so just charge per child only, or per hour only. So if you were babysitting five, charge $15 total. But don't be afraid to up the price if you feel you aren't making a worthwile job!