Key Takeaways
- 92% of companies in the UK's 2022 six-month pilot kept the four-day week after the trial ended; 57% made it permanent immediately (Boston College / 4 Day Week Global 2023)
- Employee burnout dropped 71% and staff turnover fell 57% in the UK trial, with direct cost implications for replacement hiring (Boston College 2023)
- 22% of US employers now offer a four-day workweek option, up from 14% in 2022, according to the APA's 2024 Work in America Survey
- Microsoft Japan recorded a 40% productivity gain and 23% reduction in electricity costs during its 2019 four-day week experiment
- A July 2025 study in Nature Human Behaviour covering 2,896 employees across 141 companies in six countries found 90% of companies continued the model after the trial
By 2026, the four day work week statistics are no longer theoretical. Government trials in Iceland, the UK, Spain, and Japan have produced published results. The 2025 Nature study covered 141 companies across six countries. The American Psychological Association tracked US employer adoption from 2022 to 2024. There's enough data now to go beyond pilot enthusiasm and look at what actually changes when companies cut the week to four days.
What follows is a summary of the most credible figures, where they come from, and what they don't tell you.
Four day work week statistics: key figures at a glance
| Statistic | Value | Source |
|---|---|---|
| UK pilot companies that kept four-day week post-trial | 92% | Boston College / 4 Day Week Global 2023 |
| Companies making it permanent immediately | 57% | 4 Day Week Global 2023 |
| Revenue stable or rising during UK trial | 95% of firms | Boston College 2023 |
| Average UK pilot revenue change | +1.4% | Boston College 2023 |
| Burnout reduction | -71% | Boston College 2023 |
| Staff turnover reduction | -57% | Boston College 2023 |
| Absenteeism reduction | -39% | Boston College 2023 |
| Microsoft Japan productivity gain | +40% | Microsoft Japan 2019 |
| US employers offering four-day option (2024) | 22% | APA Work in America 2024 |
| US workers who believe they could match output in four days | 81% | APA Work in America 2024 |
| Companies continuing in 2025 Nature cross-country study | 90% | Nature Human Behaviour 2025 |
The UK pilot (2022): where most of the published data comes from
The UK's 2022 six-month trial is the largest controlled four-day work week study published in English. 4 Day Week Global, Autonomy, and Boston College coordinated 61 companies with roughly 2,900 employees from June through December 2022.
Company outcomes
| Outcome | Result | Source |
|---|---|---|
| Companies continuing four-day week post-trial | 92% | Boston College / 4 Day Week Global 2023 |
| Companies making it permanent immediately | 57% | 4 Day Week Global 2023 |
| Revenue stable or rising during trial | 95% of firms | Boston College 2023 |
| Average revenue change | +1.4% | Boston College 2023 |
92% is a high continuation rate for any voluntary experiment. Companies had a clear exit option and almost none took it. The revenue data addresses the main employer objection, that shorter hours force a productivity trade-off, and across 61 companies the answer was mostly that it doesn't.
Employee outcomes
| Metric | Change | Source |
|---|---|---|
| Burnout reduction | -71% | Boston College 2023 |
| Staff turnover | -57% | Boston College 2023 |
| Absenteeism | -39% | Boston College 2023 |
| Mental health improvement (self-reported) | 54% of employees | Boston College 2023 |
| Physical health improvement (self-reported) | 46% of employees | Boston College 2023 |
| Improved sleep reported | 40% of employees | Boston College 2023 |
A 57% turnover reduction has a direct dollar value. Replacing a mid-level employee typically costs 50-150% of annual salary. When turnover drops by more than half, those savings are material.
For context on how burnout patterns connect to remote work arrangements, the remote work burnout statistics article covers the mechanisms and what the data shows about recovery rates.
The 2025 Nature study: six countries, 141 companies
A July 2025 study published in Nature Human Behaviour by Boston College researchers covered 2,896 employees across 141 companies in six countries over a six-month period. This is the largest multi-national four-day work week trial with peer-reviewed results to date.
| Metric | Finding | Source |
|---|---|---|
| Companies that continued after the trial | 90% | Nature Human Behaviour 2025 |
| Job satisfaction improvement | +0.52 points on 0-10 scale | Nature Human Behaviour 2025 |
| Burnout reduction | -0.44 points on 1-5 scale | Nature Human Behaviour 2025 |
| Mental health improvement | +0.39 points | Nature Human Behaviour 2025 |
| Physical health improvement | +0.28 points | Nature Human Behaviour 2025 |
| Employees reporting more sleep | 16% increase in reported sleep duration | Nature Human Behaviour 2025 |
The 90% continuation rate across six different countries, not just the UK, is the more significant number here. The UK trial could have reflected specific conditions in that labor market. The Nature study found the same retention pattern across regulatory environments, industries, and company sizes.
US employer adoption: the APA data
The American Psychological Association tracks employer-side adoption and employee attitudes in its annual Work in America Survey. The 2024 edition is the most current published source for US-specific data.
| Metric | Value | Source |
|---|---|---|
| US employers offering four-day option (2024) | 22% | APA Work in America 2024 |
| US employers offering four-day option (2022) | 14% | APA Work in America 2022 |
| Workers who believe they could match output in four days | 81% | APA Work in America 2024 |
| Workers who say it would make them happier | 79% | APA Work in America 2024 |
| Workers who think it will become the norm in their lifetime | 67% | APA Work in America 2024 |
| Workers who say shorter weeks would address burnout | 40% | APA Work in America 2024 |
The jump from 14% to 22% employer adoption between 2022 and 2024 is a directional shift, though still well short of mainstream. The employee side is more one-sided: 81% saying they could match output in four days is a confidence claim, not just a preference. Whether it holds across roles is a different question.
Iceland: what the post-trial data shows
Iceland's public-sector trials ran from 2015 to 2019, covering roughly 2,500 workers across 100+ workplaces. Alda (Association for Democracy and Sustainability) and Autonomy published results in 2021.
| Metric | Value | Source |
|---|---|---|
| Workers covered in trials | ~2,500 | Alda / Autonomy 2021 |
| Share of national workforce in trial | ~1% | Alda / Autonomy 2021 |
| Workplaces maintaining or improving productivity | Overwhelming majority | Alda / Autonomy 2021 |
| Workers now covered by shorter-hours agreements | 86% | Alda / Autonomy 2021 |
Iceland's case is different from a corporate pilot because of what came after. Trade unions used the trial data to negotiate shorter hours across the broader economy. By the time Alda and Autonomy published in 2021, 86% of Iceland's workers had already moved to shorter arrangements or gained the right to request them. The trial preceded the published results by years; the change had already happened.
Sectors tested included preschools, hospitals, police, social service offices, and government agencies, not just knowledge workers. Productivity was measured by service output, patient wait times, and case throughput, not by manager assessment.
Microsoft Japan (2019)
Microsoft Japan gave all 2,300 Japan-based employees Fridays off for one month in August 2019. The company tracked sales per employee, costs, and employee satisfaction.
| Metric | Result | Source |
|---|---|---|
| Productivity change (sales per employee) | +40% | Microsoft Japan 2019 |
| Electricity consumption | -23% | Microsoft Japan 2019 |
| Printer paper usage | -58% | Microsoft Japan 2019 |
| Meeting time | Reduced by ~25% | Microsoft Japan 2019 |
| Employee satisfaction | 92% reported positive | Microsoft Japan 2019 |
The 40% productivity figure is the most-cited number from this experiment, but it didn't come from the shorter week alone. Microsoft also pushed hard to cut meeting length and move routine communication to async channels. Both changes were easier to mandate when there were fewer days to pack things into. The productivity gain and the process changes came together.
Global adoption by country
| Country | Status | Year |
|---|---|---|
| Iceland | 86% of workers under shorter-hours agreements | 2021 onward |
| Belgium | Right to compressed four-day week legislated | 2022 |
| UK | Ongoing pilots; no national legislation | 2022-present |
| Spain | Government-funded pilot, 200+ companies | 2023-2024 |
| Scotland | Government pilot with 10% pay top-up for participants | 2023-2024 |
| South Korea | Pilot legislation and government trials | 2024 |
| Japan | Major employers offering voluntary option | 2021-present |
| Germany | Industry-led pilots with IG Metall union | 2024-2025 |
| Tokyo | Four-day government employee program, 160,000 staff | April 2025 |
Tokyo's April 2025 rollout for 160,000 government workers is the largest single-employer implementation on record. Japan's broader corporate adoption tells a more complicated story: fewer than 8% of eligible Japanese employees at companies offering the option have actually taken it up. Most surveys point to a coordination problem rather than a preference problem. Over 60% of eligible workers said they'd consider the option if their colleagues also took it. Nobody wants to be first.
Belgium's 2022 legislation is the clearest policy signal in Europe. Workers can request to compress contracted hours into four days rather than five, though total hours remain the same. Spain's pilot went further by testing actual hour reduction, 32 hours over four days, with government subsidies to offset the transition cost.
For context on how schedule flexibility interacts with hybrid work arrangements, the hybrid work model data covers what the research shows about scheduling formats and productivity.
Employee attitudes
| Data point | Value | Source |
|---|---|---|
| US workers who prefer a four-day schedule | 81% | APA Work in America 2024 |
| US workers who'd take a pay cut for it | 11% | Qualtrics 2023 |
| UK workers who support a four-day week | 63% | YouGov / 4 Day Week Global 2023 |
| UK pilot workers who said no pay increase would bring them back | 15% | Boston College 2023 |
| Workers who say it would address burnout | 40% | APA Work in America 2024 |
The 11% willing to take a pay cut against the 81% who'd prefer the schedule says something direct: employees want the benefit without the trade-off. The UK and Iceland pilots were built on exactly that: hours reduced, pay maintained. That's the harder ask for employers, which is part of why adoption beyond formal trials has lagged employee preference data.
For broader data on how remote and flexible work affects remote work productivity, the research covers output metrics across multiple arrangement types.
Where the model struggles
Manufacturing is the hardest case. Output ties directly to hours on the floor and you can't compress shift-based work the same way you can a calendar of meetings. The Germany IG Metall pilots are the most relevant current source for manufacturing data, though published results were limited as of mid-2026.
Customer-facing roles with five-day service expectations face logistics problems more than productivity problems. Most UK pilot companies in this category found workable solutions like rotating coverage and staggered schedules, but those transitions took more planning than the productivity adjustment did.
Regulated timelines and client-facing schedules are the most common structural objections in post-trial surveys. The companies that struggled most were those with continuous client access requirements across a standard business week.
If your team is evaluating schedule changes and you need to figure out how to cover operations with fewer internal hours, Stealth Agents provides remote staffing that can fill coverage gaps when your core team shifts to a compressed schedule.
What the data doesn't tell you
Every company in the UK and Spain pilots volunteered. Firms with structural objections didn't participate. The results describe willing companies, not a cross-section of all employers.
Most pilots ran for three to six months. The 92% UK continuation rate is a strong signal, but multi-year data on revenue trajectory, culture, and hiring is still sparse. It's possible some companies kept the policy for reasons that won't persist over a longer horizon.
The published data is also concentrated in knowledge work in specific labor markets. Iceland's trials included hospitals and emergency services, which broadens the applicability, but manufacturing, retail, and hospitality remain largely untested at scale. The Germany IG Metall pilots are the best current source for that sector.
Sources
- Juliet Schor et al., "Reduced Work Time and its Effects on Employees and Organizations," Boston College, February 2023
- Alda and Autonomy, "Going Public: Iceland's Journey to a Shorter Working Week," 2021
- Microsoft Japan, "Work-Life Choice Challenge Summer 2019," internal report, 2019
- American Psychological Association, "Work in America Survey," 2024
- Nature Human Behaviour, Boston College cross-country trial results, July 2025
- 4 Day Week Global, pilot coordination and results documentation, 2022-2023
- Qualtrics, "The Four-Day Workweek Survey," 2023
- YouGov / 4 Day Week Global, UK worker sentiment survey, 2023
- Spanish Ministry of Industry, "Pilot Programme for 4-Day Work Week," preliminary findings, 2024
- Recruit Holdings, "Work-Style Research," Japan, 2024