Small business provides about 55 percent of all jobs in the private sector.  That percent counts small-business owners working in their firms as holding “jobs” in small businesses.  Remember, these are jobs, not people (employees).  People can hold more than one job, sometimes in a large business and a small business simultaneously or in a private for-profit business and the public sector simultaneously. That makes a more refined number impossible to calculate from the data available (Source:  NFIB Research Foundation calculations from data produced by the U.S. Bureau of Labor Statistics, the U.S. Bureau of the Census, and the U.S. Small Business Administration.)