What percent of working-age Americans are employed in the public sector?

Public sector should account for all federal, state, and local government employees and funded projects with all of the involved contract workers, government funded research grants, government funded projects contracted to private industry (e.g. Intel, Boeing, Microsoft, Dell, United Technologies, Google, Bechtel, KBR, Sikorsky), all consultants contracted by the government, yearly road and highway construction and repair projects, museums and national parks services, armed services, government investigators and security organizations, teachers, police, fire departments, public servants, public attorneys, judges, prison employees, water and sewage employees, city trash, recycling services, transportation, urban planning, inspectors, all other government employees, state university employees and professors, public health employees, social workers, politicians, etc.

The first answer is completely misreading the charts on the pdf file he cites. The charts are indexed to show relative growth, not relative size.

For people that are directly on the government payroll, take a look at:
http://ftp2.census.gov/govs/apes/emp_compendium.pdf
This says about 19 million full-time equivalent jobs out of about 144 million. This site agrees, but uses the 22 million (part-time included) number for direct payroll employees.

But going beyond the direct payroll to doctors who are paid by Medicare and Medicaid patients, construction companies under contract to governments, private prison companies, etc., that’s much harder.

You can get a (poor) estimate by looking at total government expenditures:
http://www.docstoc.com/docs/5782981/Table-Total-Government-Expenditures—Historical
(currently about $3.3 trillion) and dividing by the mean personal income – approximately $46 thousand:
http://en.wikipedia.org/wiki/Personal_income_in_the_United_States
which gives you about 71 million.

This is undoubtedly high, but I have to wonder by how much.