Shaped One-Turn Inductance
This is for calculating Inductance (in microHenries) for a One-Turn, geometrically shaped inductance.
Rectangular One-Turn Coil Inductance
This is for Calculated Inductance for a One-Turn, Rectangular Loop.
For more technical data, see: F.E. Terman, "Radio Engineers' Handbook," London, McGraw-Hill, 1st ed., Sep. 1950.