An au pair is mostly paid in room and board (own bedroom and all meals provided). They are also given an allowance from $190 – $280+ a week *, demi pair allowance $140 per week.
(*dependent on age, experience and number of hours help needed, from < 25 hours to 35 hours. Demi pairs – maximum 20 hours per week help, they must attend study sessions).
But this is not the only expense when hosting an au pair. Generally there are number of additional costs.
See the other FAQ – What other costs do we need to think about?