Andrew Bibby, a UK-based freelance journalist, produces the Freelance Ready Reckoner. Although numbers for both jurisdictions are not exactly comparable due to differences in taxation levels, inflation, cost of living etc, you may find it a useful aid. Andrew writes:
The 2011 version of the Freelance Ready Reckoner (the fifth issue) is now available. For those of you who haven’t accessed it before, this aims to calculate as accurately as possible the equivalent daily income rates for UK-based freelance journalists, comparable to staff journalists’ salary levels in the range £20,000-£60,000. It looks in detail at the ‘add-on’ costs which employers meet when employing staff, including premises costs, the cos, ts involved in recruitment, staff training, pension provision, insurance and sickness.
As I put it on the Ready Reckoner FAQ section:
Q: Why have you produced the Ready Reckoner?
A: Many freelances fail to adequately appreciate when pricing their work that they are responsible for a range of costs which, were they working for an employer, would be covered by their employer. When pricing their services, it is useful for freelances to take into account what the comparable cost would be for employers if they used their own employees instead.
The Ready Reckoner can be accessed at http://www.andrewbibby.com/reckoner.html