There are several "popular" formulas. But, each of them assume that you have the ability to precisely measure the length of your leg. Every week, some guy posts in the Forums to say "I'm 5'11", with a leg length (or inseam) of 32 inches..." And, most guys who are 5'11" have a true leg length of 34, 35, or even 36 inches. So, most guys don't have a clue how to measure leg length.

The traditional method involved two steps, and NO measurements. The first step was to set the saddle height so that when the heel of your shoe was over the pedal spindle, you could smoothly back pedal, without rocking your hips from side to side, with your leg straight. The second step was to pedal with the ball of your foot over the pedal spindle...if the saddle height was correct, your knee would have a slight angle with the pedal at six o'clock, and you would not be rocking side to side on the saddle.

The traditional method generally results in a saddle position that is about half an inch lower than the math formula methods. Those methods were designed for racing, and based on assumptions involving minimum oxygen consumption/maximum watts...stuff that is important to racing, and not important to real cyclists.

Regular cyclists should care about being comfortable on the saddle, both at the beginning and end of a ride, and avoiding overstressing or injuring the knees. When the traditional method was the ONLY method, knee surgery for cyclists was almost unheard of. After the higher saddle position become popular among pro cyclists, it became the "norm" for most pro cyclists to lose a year or two of their careers to knee surgery.