One of the biggest mistakes new computer consultants make is that they don't set their fees appropriately. As you get started, you want to plan so that you can set the right prices and cover all your expenses even as you first open your consulting firm.
Although you may calculate your rates before taxes and expenses, that is certainly NOT the number you want to base your rates off. Instead, you need to take everything into consideration and go from there. Rates of $25 to $30 per hour may sound great, but you're likely to go broke that way.
If you must estimate your expenses, overestimate rather than underestimate. If you underestimate, your business and your personal life will go bankrupt quickly. Prove your services and your clients will be more than willing to pay the price.
Learn more about pricing in the complete article (link above).
Added by Computer Consulting 101