The average salary in the US is $41673 or neatly converted into £26,000.....the average wage in the Uk is £26,400.....allthough if you live down south or in/around London thats considered a low wage and is more like £40,000+ average.
Average US Salary in terms of GDP per capita (at purchasing power parity) for 2011 was $48,147 whilst in Britain where things are bloody more expensive it was $35,974 and yes that includes inner city new york and the bits of London full of Russian 'businessmen'.