What is the aveage forehead size of an adult male forehead?

The average forehead size of an adult male typically measures between 5 to 6 inches (about 12.7 to 15.2 cm) in height. However, this can vary based on individual differences and ethnic backgrounds. Forehead width can also vary, but there isn't a widely accepted standard measurement for it. Overall, forehead size is influenced by various factors, including genetics and age.