By Daniel Hunter

Female managers are effectively working for free nearly two hours every day because of the gender pay gap, according to new research from the Chartered Management Institute (CMI).

The survey of 72,000 managers in the UK found that women working in equivalent full-time roles earn 22% less than men, meaning that they are unpaid for 1hr 40m a day — a total of 57 working days every year.

However, the study did find that the gap is closing. For men and women of all ages and in all professional roles the gender pay gap now stands at £8,524, with men earning an average of £39,136 and women earning £30,612. In 2014, the pay gap stood at £9,069, or 23%.

The pay gap rises to £14,943 for senior or director-level staff, with men earning an average of £138,699 compared to the average for women of £123,756. Female managers are also missing out across all levels when it comes to bonuses, with the average man’s bonus of £4,898 almost doubling that of the average woman’s bonus of £2,531.

The survey data also reveals that the pay gap becomes wider as women grow older. Women aged 26-35 are paid 6% less than their male colleagues, rising to 20% for women aged 36-45. The gap increases to 35% for women aged 46-60, equivalent to working 681 hours for free compared to their male colleagues. For women and men in their 60s the pay gap expands to 38%.

Not only are older women earning less, but there are also fewer of them in executive positions. Even though women comprise 67% of the workforce in entry-level roles, and continue to outnumber men in junior management roles, female representation drops to 43% at the level of senior management. Just 29% of director-level posts are held by women. In March, the publication of Women on Boards: Davies Review Annual Report 2015 revealed that the number of women holding board-level positions in FTSE 100 companies reached 23.5% - just short of the 25% target.

Ann Francke, chief executive of CMI, said: “Working for free two hours a day is unacceptable. While some progress is being made, it’s clear from our research that Lord Davies is right to target the executive pipeline. Having more women in senior executive roles will pave the way for others and ensure they’re paid the same as their male colleagues at every stage of their careers.”