In 2004 I examined several formulas by Johns, Robinson, Molero, Jumen, Raymundo, Flores and others. They all failed to give adequate results and then I started collecting athlete's data and after 10 years of experience I created my own formula.
This calculator gives the optimal lean body mass for a complete athlete.
Biceps circumference relaxed cm and flexed cm
Natural Male Maximum Lean Body Mass
This formula by Casey Butt shows the maximum muscular development without use of anabolic steroids.
Enter height and wrist data in Optimal Weight section, set sex to male.