Women who retired in 2017 were £6,400 a year worse off than men – up from £5,400 in 2016, research from Prudential has found.
Women expect an annual retirement income of £14,300 compared to £20,700 for men.
Half of women reckoned they are financially prepared for retirement.
Kirsty Anderson, a retirement income expert at Prudential, said: “The gender gap in retirement incomes continues to grow, probably reflecting the fact that many women will enter retirement having taken career breaks and changed their working patterns to look after dependants.
“Unfortunately, as a result, many women will end up with smaller personal pension pots and some are also likely to receive a reduced state pension.
“However, with a greater number of women staying in the workforce for longer these days, and employers increasingly offering more flexible working patterns, the outlook looks more positive for women’s retirement incomes in the future.”