I thought current federal spending was about $3.7T.
My numbers came from this site: http://www.usgovernmentspending.com/
You are correct with regards to FEDERAL spending. I was referencing TOTAL (Fed + state + local) spending. The 42% represents the total tax load on US citizens.
If we look at it from just the Federal level. The break even point is between 24% and 25%. Again, that is without any spending cuts.