Since your nanny is considered a household employee, she is covered by the Fair Labor Standards Act. Nannies are considered "nonexempt" employees, which means they are officially paid an hourly wage and are entitled to overtime compensation (1.5 times the hourly rate for any hours worked over 40). That is why you should list an hourly wage in your work agreement, even if you have a target weekly amount in mind. The calculator below
The best way to protect yourself and avoid any disputes about overtime pay is to have your nanny fill out a weekly time card. This sheet not need to be complicated. The picture above includes a link to a sample time sheet. Each day, all you or your nanny need to do is fill in the time your nanny begins and ends work as well as the length of any breaks. Each time sheet has room for four weeks. After the fourth week, both you and your nanny can review the time sheet and sign it. Keep the signed time sheet for your records.