arduino 5v out

Hi I know that the arduino board can ouput 5v or 9v but at what mA ?

-about 400ma from the 5V reguator (it is rated for 500ma; reserve about 100ma for the Atmega, FTDI chip etc.) - half an amp or more from the 9V. this is connected to the power adapter input through a diode, so the amount of current you draw through that pin will be limited by the diode's rating.