About 710,000 people work in Philadelphia every day, and about 457,000 of them live in the city, the data show.
Montgomery County is the biggest source of out-of-town commuters, with 60,159 residents traveling to Philadelphia to work each day. A similar number of Philadelphia residents - 60,551 - commute from the city to work in Montgomery County.
Delaware County sent 51,457 residents to work every day in Philadelphia, while there were 17,732 reverse commuters from Philadelphia to Delaware County.
Bucks County sent 33,877 residents to work in the city, while attracting 26,028 from Philadelphia.
Chester County sent 11,425 residents to work in Philadelphia, while drawing 7,306 city residents.
There was a bigger net inflow of commuters from South Jersey, with about 47,000 more people coming to the city than leaving for work.
Camden County sent 32,269 residents across the Delaware to Philadelphia, while 8,822 went the other way.
Burlington County sent 16,327 residents to work in Philadelphia, while drawing 6,731 city residents.
Gloucester County sent 15,932 residents to work in Philadelphia, while attracting 2,116 Philadelphians.
The estimates released from the American Community Survey also showed the average one-way commute to work for people living in Philadelphia was 31.5 minutes in 2011, compared with the national average of 25.5 minutes.
Contact Paul Nussbaum at 215-854-4587 or firstname.lastname@example.org.