Lack of adequate sleep is costing the UK economy as much as £40bn ($50bn) a year in lost productivity, according to a new study.
Researchers at Rand Europe said Britain loses 200,000 working days a year due to sleep deprivation among its working population.
Sleeping less than seven hours a day leads to a higher mortality risk and lower productivity levels among the workforce through a combination of absenteeism and employees being present at work but working at a sub-optimal level.
The losses stemming from this cost the country 1.86% of its gross domestic product.
The study, which was compiled by collecting data from 62,000 people, found that increasing nightly sleep from under six hours to between six and seven hours could add £24bn to the UK economy per year.
Marco Hafner, the report's lead author, said: "Our study shows that the effects from a lack of sleep are massive.
"Sleep deprivation not only influences an individual's health and wellbeing but has a significant impact on a nation's economy, with lower productivity levels and a higher mortality risk among workers.
"Improving individual sleep habits and duration has huge implications, with our research showing that simple changes can make a big difference."
The report called on employers to recognise the importance of sleep and build facilities for employees to take daytime naps.
It urged working adults to set consistent wake-up times and limit the use of electronic devices before bedtime.
"The emerging science around sleep shows it to be a central risk for people's productivity, physical health, mental health and mortality," Shaun Subel, strategy director at VitalityHealth, said.
"Given its breadth of influence, it is crucial to find meaningful ways to improve the amount and quality of sleep we get."
Rand Europe also analysed the impact of lack of sleep among workers in the US, Canada, Germany and Japan.
The US was found to have the biggest financial losses of $411bn as a result of lack of sleep, while Canada had the best sleep outcomes but still lost $21.4bn a year.