We need to know how many children, their ages, nanny's responsibilities, breakdown of the 30 hours (you'll pay more for 6hrs 5 days a week than you will for three ten hour days IMO - it'd be easier for her to have a second job in the latter scenario), and if she will be live in or out at the very least before we can give you a price range. Then there are additional details such as how much experience you want, are there any children with special needs, do you want the nanny to have a college degree, etc. which will also affect rates. In general, however, $15/hr is your on-the-books minimum rate (a little less if you're paying under the table which is a disservice to the nanny and I do not condone) for one child and a somewhat (1-3 years) experienced nanny.

Start talking with people who want the job and they'll tell you.

How much could I expect to pay a (legal, obviously) nanny for 30 hours per week in SW DC hourly? What about for healthcare, etc.? Feeling totally overwhelmed! Thanks so much for any advice.