When can a minor claim exempt on a W-4?

The absolute maximum earned wages I expect is $15,000. I've already paid about $260 in federal income tax, and according to the IRS withholdings calculator, I would only need to pay $21 when I file my taxes if I claimed exempt now. However, I doubt I will make that much. My parents can and will claim me as a dependent and I expect no other income in 2019.