An employer will offer you a salary that is below this amount. You need to know how low you can go. Salary is often based upon value and your ability to produce. You will need to know your market value. Based on salary ranges, your education and experience, and your skills and capabilities, you need to personally assess what you are worth.
Many people make the mistake of naming a figure in the middle of a salary range.
Ask yourself why you don't deserve the top. It's easy to be impressed by a salary more than you've been earning only to resent two months later that you didn't ask for more. Often, you will be asked about your salary requirements in the initial stages of the job interview process, perhaps even in the letter of application. Having done your homework, you may provide the employer with your salary range. Do not give one specific amount.