Someone just told you that he has a farm in the countryside that spreads across two acres.

This would have much easy for you to visualize had you known that an acre is roughly the equivalent size of nine basketball courts or three Olympic-size swimming pools.

Enter Sensible Units - a web based unit conversion service that helps you visualize complex units and measurements using real and more sensible objects like CDs, golf ball, Harry Potter books, elephants or even AA batteries.

So 10 kilometres are like putting 23 Empire State building on top of each other, 100 meters is like 12 double-decker buses standing end to end while 100 GB is the same as 62 installations of Windows XP or 12 Windows Vista installations.