In one in three families in the U.S., or 38.1 percent, the wife is the primary breadwinner, according to data from the Bureau of Labor Statistics (BLS).
In 2012, which is the latest data from the BLS, there were 36,181,000 married-couple families in which the wife, but not necessarily the husband, had earnings from work. Of those, there were 13,779,000 families in which the wife earned more than her husband. This means that 38.1 percent of families had wives earning more than their husbands.
The BLS has been tracking these data since 1987, and at that time in 23.7 percent of families, the wife was the primary earner. This means that since 1987 to the present, wives earning more than their husbands has increased by 60.8 percent.