A few years ago, a four-day work week sounded like a perk reserved for tech utopias and Scandinavian fantasy. Now it is a real strategy that hundreds of companies across a dozen countries have actually tested, tracked, and in most cases kept.
The interesting part for anyone running a business is not the idea itself, it is what the data from these trials actually shows once the pilot ends and the spreadsheets come out.
Here is what leaders considering this shift should actually know, based on real trial results rather than the usual “work less, live more” pitch.
What a Four-Day Work Week Actually Means
The four-day work week usually follows a model called 100:80:100 principle. Employees work 80% of their normal hours (typically 32 instead of 40), keep 100% of their pay, and are expected to maintain 100% of their previous output.
That is different from a compressed schedule, where employees simply work four 10-hour days instead of five 8-hour days. Compressed schedules keep the same 40-hour total and tend to cause daily fatigue and higher stress, since nothing about the actual workload changes.
The 100:80:100 model works because it forces companies to redesign how work actually gets done, cutting meetings, reducing admin, and eliminating low-value tasks instead of just squeezing the same hours into fewer days.
What the Trials Have to Say About Companies With Four-Day Work Weeks
| Company or Trial | Model Tested | Result |
| Microsoft Japan | 4 days on, 3 off, full pay | 40% increase in productivity |
| Perpetual Guardian (New Zealand) | 32-hour, 4-day week | 20% increase in hourly output |
| British Telecom | Wellbeing tracking | 13% more sales during high-wellbeing weeks |
| Irish SME Pilot | 100:80:100 model | 25% boost in hourly output |
| German National Pilot | 100:80:100 model | Stable output, revenue neutral |
Beyond productivity, the financial picture holds up too. The 2022 UK trial across 61 companies saw revenues rise 1.4% during the trial period, up 35% year over year.
Ireland’s national pilot recorded an 8% revenue increase during the trial and zero companies losing money. South Africa’s trial averaged a 10.5% revenue gain. None of the major national pilots reported companies losing revenue as a direct result of the shorter week.
The Benefits of a Four-Day Work Week, Backed by Real Numbers
Across UK, Irish, South African, Australasian, and Brazilian pilots, self-reported burnout dropped between 57% and 71%, and stress scores fell by similar margins. This proves that the human side of the data is just as striking as the productivity numbers making the headlines.
That translates directly into fewer sick days. The UK trial saw a 65% drop in sick leave. Australia recorded a 44.3% drop in monthly sick and personal leave. Unilever New Zealand documented a 34% drop in absenteeism. Employees also slept more, gaining roughly 38 to 42 extra minutes per night in the German and Irish trials.
The benefits of a four-day work week extend into hiring too. UK turnover fell 57% during the trial period. One Australian company reported a 600% jump in job applications after switching.
Across global datasets, 63% to 83% of businesses following the model reported an easier time recruiting and retaining talent, which is a big deal in a labor market where employees increasingly treat flexibility as a real benefit, not a nice-to-have.
Four-Day Work Week Countries: Who Is Actually Doing This
The UK ran the world’s largest trial in 2022 across 61 companies, with 92% keeping the schedule permanently afterward. Iceland’s earlier public sector trials effectively secured reduced hours or the right to negotiate them for 86% of its national workforce.
In Asia, Japan’s government is actively pushing shorter weeks to fight karoshi, its term for death from overwork, and Tokyo mandated four-day options for 160,000 public employees in 2025.
The UAE became the first country to adopt a federal workweek shorter than five days back in 2022. Belgium gave workers the legal right to request a compressed four-day schedule in 2022, and Lithuania grants public sector parents of children under three a 32-hour week at full pay.
In the United States, adoption is mostly private sector so far. A federal bill from Senator Bernie Sanders and Representative Mark Takano would gradually lower the overtime threshold from 40 to 32 hours, and New York has a state bill proposing pilot programs and tax credits for companies that make the switch.
Nothing has passed yet, but the fact that it is being seriously debated in Congress says something about how far this idea has traveled from its “tech company perk” origins.
Where the Model Actually Breaks Down
Continuous, 24/7 sectors like healthcare, transport, hospitality, and manufacturing cannot just cut hours. They must fill gaps with overtime or new hires. That adds cost instead of saving it.
A well-known cautionary example comes from Sweden’s 2015 Gothenburg trial, where a public hospital cut nursing shifts to six hours at full pay. Patient care improved, but the hospital had to spend $120,000 a month on replacement staff. The program was eventually cancelled because the cost was too high to sustain.
Unilever and Bupa in Australia also walked back rigid four-day mandates after running into coordination issues across large, complex business units, shifting instead toward more flexible arrangements.
There is also a real equity concern buried in the data. Shortening the workweek without clear pay protections could reduce hourly workers’ income, while salaried employees keep the same schedule and full pay. That is exactly the fight labor groups have raised over a proposed bill in Washington State, and it is a genuine reason this shift needs careful design, not just enthusiasm.
The Bottom Line
The evidence on the four-day work week is no longer speculative. Across many national and corporate trials, the results are similar: productivity stays the same or improves, burnout and sick days decrease, and companies retain more employees. However, these benefits depend on redesigning work processes rather than simply fitting five days of work into four.
For business leaders weighing whether to run a pilot of their own, the biggest predictor of success is not the industry, it is whether leadership is actually willing to redesign how work gets done rather than just changing the calendar.
FAQs
What is the four-day work week 100:80:100 model?
It means employees work 80% of their normal hours, which is usually 32 instead of 40, while keeping 100% of their pay and being expected to maintain 100% of their previous output with better workflow.
Which companies with four-day work weeks have seen the best results?
Microsoft Japan reported a 40% productivity increase, Perpetual Guardian in New Zealand saw a 20% jump in hourly output, and Irish SMEs in a national pilot recorded a 25% boost, all while maintaining full pay.
Which four-day work week countries have made the most progress?
The UK, Iceland, Belgium, Japan, and the UAE have made significant progress, from large national trials and legal rights to request shorter work schedules to the UAE’s shorter federal workweek.
What are the biggest benefits of a four-day work week for employees?
The clearest benefits are reduced burnout and stress, fewer sick days, better sleep, and stronger retention, with several national trials reporting burnout drops between 57% and 71%.
Does a four-day work week work for every industry?
No. Continuous-coverage sectors like healthcare, transport, and manufacturing struggle to cut hours without hiring extra staff or paying overtime, which is why adoption has been strongest in knowledge-based and office-based industries so far.
Neelmani Yadav
