Watts supply thing

How many watts are supplied by an arduino Uno from the 5v port

thanks in advance

NineNinjas911

The power dissipated by the on board regulator should be kept under 1 Watt. That means that the max current is dependent on the voltage supplying the regulator. The higher the supply voltage, the lower the current to keep the dissipation under 1W. For instance, if 12V is supplied to Vin the regulator must drop 7V. 1W / 7V = 143mA max current. If the supply is 7.5V then the drop is 2.5 and the max current is 400mA.

Thanks