In Google's words:

The calculator can evaluate mathematical expressions involving basic arithmetic (5+2*2 or 2^20), more complicated math (sine(30 degrees) or e^(i pi)+1), units of measure and conversions (100 miles in kilometers or 160 pounds * 4000 feet in Calories), and physical constants (1 a.u./c or G*mass of earth/radius of earth^2). You can also experiment with other numbering systems, including hexadecimal and binary.

So give it a try, enter something you want to calculate in the box below and hit "Google Calculate".