40% mums in US are main or sole breadwinners

In 1960, that figure was just 11%, according to a Pew Research Center study

Women in America are the sole bread earners in nearly half the households with kids, a new survey has revealed.

Forty percent are either the main or only wage earners in their families -- a huge jump from 1960, when that figure was 11 percent, the Pew Research Center found in the study.

The researchers found that about a quarter of married mothers are making more than their spouses, the New York Daily News reported.

Those moms are really raking it in, too - their families boasted a median income of $80,000, which is much higher than the nationwide figure of $57,100 for all families with kids, according to the study.

But the income gap between the families with moneymaking mums and families in which mothers struggled to make ends meet was stark.

In 8.6 million households headed by single moms, the annual median income was just $23,000, Pew found.

The Pew research appeared to mirror results in an April report by The New York Women's Foundation, which found that single moms were the most "economically insecure."

Part of the reason why the ladies have increasingly become the breadwinners is because, at 47 percent, they make up almost half of the US labour force, Census Bureau figures show.

The employment rate of married mothers with children nearly doubled from 37 percent in 1968 to 65 percent in 2011.