well i dont understand what you mean scale form, if you are talking about A pay scale (also known as a salary structure) is a system that determines how much an employee is to be paid as a wage or salary, based on one or more factors such as the employee's level, rank or status within the employer's organization, the length of time that the employee has been employed, and the difficulty of the specific work performed. than we can calculate there earnings by tax slab and we can find how much they have to give tax.