It can be calculated by knowing the number of milligrams of protective colloid which is sufficient to prevent the coagulation of 10 ml of the gold standard solution on addition of 1 ml of 10% Sodium chloride solution.
It is represented as the measure of efficiency to protect a colloidal solution from precipitation.
If the value of the golden number is lower, the protective power of the colloid will be greater because it is inversely proportional to the first.
Hence, The gold number can be calculated from the number of milligrams of protective colloids.