I'm trying to understand how to calculate the strength of the magnetic field generated by a current loop. What I know so far is: When a current moves around a loop of wire it generates a magnetic field which looks a bit like that of a solenoid, only not so concentrated through the center of the loop. The magnetic field at the center of the current loop is calculated by: I understand what each of the terms mean except the term L and the term r (with the ^ above). What I'd like to know is: How is this equation derived? What are the terms I don't recognise? Is there a way to calculate the magnetic field strength at any point on the plane that the loop lies in? Thanks in advance!