Web-based Antenna Designer and Calculator
/Rob (DM1CM) has created a website for all of us who find trying to understand EZNEC, 4NEC2 and similar packages too hard. Rob says that while the site is simplified and concentrates on common wire antennas, it is still fairly accurate as behind the screen he is using antenna modelling software. As the work is not done on your local PC some operations can take a little while to complete but be patient and it will get there.
As well as supplying dimensions for you to build one of the four "standard" antennas (Linked Dipole, End-Fed-half-wave, Delta Loop or Half Square (more to be added)), it also shows you the propagation pattern, VSWR charts, antenna current diagram and the smith chart for the chosen antenna.
More Information - https://sota-antennas.com/