For actual employees who work in a web design office or in an office for a company designing websites the web designers earn on average of $51,000.00 to $76,000.00 per year.
Now when you're working as a freelance web designer the salary will depend on how many websites you design and how much you get paid but some freelance web designers earn $20,000.00 to $50,000.00 per year but I've read on some forums that a few freelance web designers were earning up to $150,000.00 per year.
Now if whether that's true or not I can't say for sure but I guess if you're really skilled and can charge a good amount for the professional web design then you could be earning $150,000.00 per year.