What is a standard billing rate to salary ratio?

I just read Colin Cameron's answer and I think he failed to make a key point. This one third ratio applies to Total Salary account. So if you are an "Influencer" or what was called in the old days an Account Executive, operating on his own, with zero Management Supervision or Support structures like Secretarial, Human Resources, IT services, Media Services, Cleaning and Coffee making. Only then can you pay yourself about one third. If, however, you are an Acct Exec  reporting to a Manager or Director and no additional services the total salaries of the Two of you can come to one third and so on. 

There is no standard billing to salary ratio. What you do is take to salary add on fringes(medical, pensions , vacation, and other benefits) then on top of this the profit you want to make, which can vary all over the place. For example you might have someone making $50.00 per hour with a 50% fringe rate or $25.00 per hour for a total of $75.00 per hour. Then on top of this you might want a 20% profit or $15 so the billing rate would be $90.00 per hour.