What do you charge for babysitting?

i charge $12 an hour. im 18 and ive been babysitting off and on for a couple of years, never anything regular really. and as for how i picked my rate, i just googled a lot of stuff about it, and picked $12. also, the family i am babysitting for right now, the mom asked my rates and i said 12, she said that she normally pays 12 at night and 15 in the day as the kids need more attention in the day because theyre awake