How many technology businesses are in Philadelphia?

There are nearly 500 technology companies in Philadelphia city and some 5,100 in the region, according to federal data evaluated by the Center City District and shared with Technical.ly Philly.

The average size of a tech firm in the 11-county region rings in at 16.5 employees, according to 2011 County Business Patterns data from the U.S. Census Bureau. There are 2012 sources but these 2011 figures are the most recent, complete data, said Center City District research and analysis manager Lauren Gilchrist.

To get an even deeper look into the early-stage tech companies in this number, Technical.ly Philly is hosting a Philly Tech CEO and founders Survey. We’ve extended the deadline this week: take the 10-minute survey here.

Definitions in the fast-moving tech sector are challenging, as software and digital strategies seep into nearly every corner of the economy, but there has been an effort to start somewhere.

Gilchrist cribbed a definition from the Downtown Alliance of NYC, which developed its own, using federal IRS classifications [PDF]. Using those specifications, listed in detail below, Gilchrist says there are 488 tech firms in the 135 square miles of Philadelphia city as of this year. In the 11-county Philadelphia region, there are 5,100, she said.

Don’t assume most of those companies are one-person freelance outfits, as just a smattering of them are sole proprietorships. Parsing even further down to what a tech startup presents its own challenges, so this is focused on IT firms at large.

This structure uses select NAICS codes:

• 334-All six-digit NAICS under Electronic Computer Manufacturing
• 3353–All six digit NAICS codes under Electrical Equipment Manufacturing
• 454111-Electronic Shopping
• 454112-Electronic Auctions
• 511210–Software Publishers
• 518210-Data Processing, Hosting, and Related Services
• 519130-Internet Publishing and Broadcasting and Web Search Portals
• 5415- All six-digit NAICS codes under Computer Systems Design and Related Services,
• 519110- News Syndicates
• 519120–Libraries and Archives
• 519190– All Other Information Services
• 541830 -Media Buying Agencies
• 541840 –Media Representatives
• 611420–Computer Training
• 54171-Scientific Research and Development Services