Docedison:
The Arduino Uno R3 quiescent current is more like the 60 to 80 mA total power LED draws Lefty mentioned.
About 10 - 20 mA each for the processors (328 and 16U) about 10 mA of various bias currents and 5 to 10 mA for the regulator does add up to more than 5 to 20 mA total.Bob
Thanks, and I was going mostly on memory of past posting of other peoples actual measurement of board current consumption, which in the end is the final answer for the OP's question. measure twice, cut once. 
Lefty