The most common way to determine 6’ 5″ ideal weight is to look it up on a BMI chart, but some tables do not include 6 foot 5 inchs.
A healthy BMI for someone 6′ 5” is between 156 pounds and 211 pounds. The BMI does not give different ideal weights for men and women.
BMI is currently what is used by the cdc and other health related agencies
Other formulas for choosing ideal weight are:
Ideal Weight for Women 6’ 5″
Robinson Formula - 171 pounds is ideal weight for a woman
Devine Formula - 186 pounds is ideal weight for a woman
Miller Formula – 168 pounds is the ideal weight .
Ideal Weight for Men 6’ 5″
Robinson Formula – 185 pounds is the ideal weight for men
Devine Formual – 196 pounds is the ideal weight for men
Miller Formula – 176 pounds is the ideal weight for men