90% of companies that piloted a four-day workweek kept it after six months (Nature Human Behaviour, Fan and Schor, 2025). That figure comes from the largest peer-reviewed trial to date, which tracked 2,896 employees across 141 organizations in six countries against a 562-person control group. The UK’s own 2022 pilot pointed the same way: 56 of 61 companies (92%) continued, with staff turnover down 57% and burnout reported lower by 71% of workers (Autonomy, 2023). The debate has shifted from whether the model works to how far it spreads. This analysis consolidates data from Nature Human Behaviour, 4 Day Week Global, the Autonomy Institute, the 4 Day Week Foundation, Gallup, the American Psychological Association, and 8 other primary sources to map what the numbers actually show heading into 2026.
TL;DR
- The largest peer-reviewed trial (2,896 employees, 141 organizations, six countries) found 90% of companies kept the schedule after six months (Nature Human Behaviour, 2025).
- Burnout fell 0.44 points on a five-point scale and job satisfaction rose 0.52 points on a ten-point scale (Nature Human Behaviour, 2025).
- In the UK 2022 pilot, 56 of 61 companies (92%) kept the four-day week and 18 made it permanent (Autonomy, 2023).
- UK pilot staff turnover dropped 57% while revenue rose 35% versus comparable prior periods (Autonomy, 2023).
- The US and Ireland pilot lifted revenue about 8% over the trial and 38% against the same six months a year earlier (4 Day Week Global, 2022).
- 22% of US employers offered a four-day workweek in 2024, up from 14% in 2022 (APA, 2024 Work in America Survey).
- Just 8% of US full-time employees actually work a four-day week (Gallup, 2022, most recent available).
- 81% of US workers support a four-day week and nearly 90% would sacrifice something to get it (Bankrate, 2023).
- Over 200 UK employers with 5,000+ workers are permanently accredited four-day-week companies (4 Day Week Foundation, 2025).
- The 4 Day Week Foundation’s 2025 UK pilot kept all 17 firms on reduced hours, with 62% of staff reporting lower burnout (4 Day Week Foundation, 2025).
- Tokyo’s metropolitan government opened a four-day-week option to employees from April 2025 (Tokyo Metropolitan Government).
- 4dayweek.io lists 19,350+ reduced-hours jobs at 1,500+ companies (4dayweek.io, 2026).
1. Adoption and Prevalence
Interest and reality diverge sharply. Employer offerings have grown fast, but the share of workers on an actual four-day schedule is still a rounding error. US employers offering a four-day workweek climbed to 22% in 2024, up from 14% in 2022 (APA, 2024 Work in America Survey), yet Gallup’s headcount of who genuinely works four days sits at 8%. The gap is the story of 2026: policy availability is outrunning day-to-day practice, and the accredited-employer registries in the UK show where formal, full-pay adoption is concentrating. For the broader flexibility backdrop, see our remote work statistics.
| Metric | Value | Source |
|---|---|---|
| US employers offering a four-day workweek (2024) | 22% | APA, 2024 Work in America Survey |
| US employers offering a four-day workweek (2022) | 14% | APA, 2024 Work in America Survey |
| US full-time employees actually working four days | 8% | Gallup, 2022 (most recent) |
| US full-time employees working five / six days | 84% / 8% | Gallup, 2022 |
| UK employers permanently accredited (full pay; workers covered) | 200+ (5,000+) | 4 Day Week Foundation, 2025 |
| UK companies on four-day / reduced-hours with full pay | 337 | 4dayweek.io, 2026 |
| Reduced-hours jobs listed on 4dayweek.io (companies) | 19,350+ (1,500+) | 4dayweek.io, 2026 |
Source: American Psychological Association, 2024 Work in America Survey coverage and 4dayweek.io UK company registry.
Note: Gallup’s 2022 read (12,313 full-time employees) remains the most recent nationally representative count of actual four-day workers; it is up from 5% in 2020.
2. The Landmark Trials: Pilot Outcomes
The credibility of the four-day week rests on a small number of structured trials with published data, not anecdotes. The peer-reviewed six-country study of 2,896 employees found 90% of participating companies kept the schedule after six months (Nature Human Behaviour, 2025) — the strongest independent evidence yet, because it used a 562-person control group rather than self-selection alone. The UK’s 2025 Foundation pilot went further, with every firm retaining the model.
| Metric | Value | Source |
|---|---|---|
| Employees / organizations / countries in peer-reviewed trial | 2,896 / 141 / 6 | Nature Human Behaviour, 2025 |
| Companies keeping the schedule after six months | 90% | Nature Human Behaviour, 2025 |
| UK 2025 Foundation pilot firms keeping four-day week | 17 of 17 (100%) | 4 Day Week Foundation, 2025 |
| UK 2025 pilot firms moving to a full four-day week | 12 of 17 | 4 Day Week Foundation, 2025 |
| UK 2025 pilot firms adopting a nine-day fortnight | 5 of 17 | 4 Day Week Foundation, 2025 |
| UK 2025 pilot workers covered | 1,000+ | 4 Day Week Foundation, 2025 |
| UK 2022 pilot companies continuing | 56 of 61 (92%) | Autonomy, 2023 |
| UK 2022 pilot permanent adopters | 18 | Autonomy, 2023 |
Source: Nature Human Behaviour, Work time reduction via a 4-day workweek (Fan and Schor et al., 2025) and The Autonomy Institute, UK four-day week pilot results.
Note: the peer-reviewed study’s authors flag limits — smaller companies, higher-income countries, and self-reported data — so its 90% should be read as trial-continuation, not economy-wide.
3. Productivity, Revenue, and Business Performance
The commercial case is what converts skeptical executives, and the trial data on revenue is more favorable than most expected. UK pilot revenue rose 35% against comparable prior periods (Autonomy, 2023), while the US and Ireland cohort posted an 8% gain over the trial window. Retention gains compound the effect: turnover fell by more than half in the UK, and Exos more than halved its own attrition. Since meetings are a prime target when hours get compressed, the math connects to our meeting cost statistics.
| Metric | Value | Source |
|---|---|---|
| UK pilot revenue vs. comparable prior periods | +35% | Autonomy, 2023 |
| UK pilot revenue change (weighted, over trial) | +1.4% | Autonomy, 2023 |
| UK pilot staff turnover change | -57% | Autonomy, 2023 |
| US / Ireland pilot revenue over the trial | +8% | 4 Day Week Global, 2022 |
| US / Ireland pilot revenue vs. same six months prior year | +38% | 4 Day Week Global, 2022 |
| US 12-month follow-up: self-reported work ability increase | 57% | 4 Day Week Global, 2023 |
| Exos annual employee turnover (2022 to 2023) | 47% to 29% | Exos / CNBC, 2024 |
| Portugal companies reporting a performance rise | 85% | Birkbeck and Henley, 2024 |
Source: 4 Day Week Global, US and Ireland pilot results and CNBC on Exos one year later.
Outlier note: the UK’s +35% figure is measured against similar prior periods, whereas the +1.4% is the weighted change during the trial itself; both come from the same Autonomy report and describe different windows.
4. Burnout, Health, and Wellbeing
Wellbeing is where the four-day week posts its most consistent results across every trial, regardless of country. Burnout dropped 0.44 points on a five-point scale and job satisfaction climbed 0.52 points on a ten-point scale (Nature Human Behaviour, 2025), with mental health also improving measurably. These are protective, not clinical, findings — reduced hours correlate with lower self-reported strain, and the effect scaled with the size of the hours cut. For the flip side of the ledger, see our sibling workplace burnout statistics.
| Metric | Value | Source |
|---|---|---|
| Burnout change (five-point scale) | -0.44 | Nature Human Behaviour, 2025 |
| Job satisfaction change (ten-point scale) | +0.52 | Nature Human Behaviour, 2025 |
| Mental health change (five-point scale) | +0.39 | Nature Human Behaviour, 2025 |
| Staff reporting reduced burnout (UK 2025 pilot) | 62% | 4 Day Week Foundation, 2025 |
| Staff reporting better work-life balance (UK 2025 pilot) | 45% | 4 Day Week Foundation, 2025 |
| Work exhaustion reduction (Portugal pilot) | 19% | Birkbeck and Henley, 2024 |
| Fatigue reduction (Portugal pilot) | 23% | Birkbeck and Henley, 2024 |
| US 12-month follow-up burnout reduction | 69% | 4 Day Week Global, 2023 |
Source: Nature Human Behaviour study and 4 Day Week Global, Portugal pilot results.
Note: physical health also improved 0.28 points on the same five-point scale in the peer-reviewed study, with the largest gains among workers who cut a full eight-hour day.
5. Worker Sentiment and Demand
Employee demand is the political engine behind every pilot, and the surveys are lopsided. 81% of US workers support a four-day week, and nearly 90% would sacrifice something to secure one (Bankrate, 2023) — including 54% willing to work longer daily hours. The willingness to trade pay or job for the schedule is what makes it a recruiting lever; the extra day is increasingly spent on second income streams, a link explored in our side hustle statistics.
| Metric | Value | Source |
|---|---|---|
| US workers supporting a four-day week | 81% | Bankrate, 2023 |
| Workers who would sacrifice something to get it | ~90% | Bankrate, 2023 |
| Workers who would work longer daily hours for it | 54% | Bankrate, 2023 |
| Believe they would be happier and equally productive on four days | ~80% | APA, 2024 |
| On-site employees who would change jobs for a four-day week | 44% | Gallup, 2022 |
| Say a four-day week at same pay is a top attraction benefit | 63% | Gartner, 2024 |
| US pilot employees wanting to continue | 95% | 4 Day Week Global, 2023 |
| UK staff: no pay raise would return them to five days | 15% | Boston College and Cambridge, 2023 |
Source: Gallup, Is the 4-Day Work Week a Good Idea? and APA coverage of the Work in America Survey.
Note: Gallup’s engagement analysis cautions that the quality of the work experience carries 2.5x to 3x the weight of the number of days worked, so schedule alone does not guarantee wellbeing.
6. Global Rollouts and Government Programs
The four-day week is no longer an Anglo-American experiment; national governments and city administrations are now the ones scaling it. By 2021, 86% of Iceland’s workforce had moved to shorter hours or won the right to them after trials covering roughly 2,500 workers (Alda and Autonomy, 2021) — the deepest population-level shift on record. Germany’s cohort held up on follow-up, and Tokyo’s rollout signals that demographic policy, not just productivity, is now driving adoption in Asia.
| Metric | Value | Source |
|---|---|---|
| Iceland trial participants (2015 to 2019) | ~2,500 | Alda and Autonomy, 2021 |
| Iceland workplaces in the trials | 66 | Alda and Autonomy, 2021 |
| Icelandic workforce on shorter or entitled hours (2021) | 86% | Alda and Autonomy, 2021 |
| Germany pilot organizations | 45 | 4 Day Week Global, 2026 |
| German orgs continuing reduced hours (two-year follow-up) | 70% | 4 Day Week Global, 2026 |
| Portugal pilot companies (coordinated six-month trial) | 41 (21) | Birkbeck and Henley, 2024 |
| Tokyo metropolitan government four-day option | Launched April 2025 | Tokyo Metropolitan Government |
Source: 4 Day Week Global, Germany pilot results and NBC News on Tokyo’s four-day workweek.
Context note: Iceland’s trials reduced weekly hours (to roughly 35 to 36) rather than mandating a literal four-day week, so the 86% figure covers shorter-hours arrangements broadly, per Washington Post reporting.
Summary: Four-Day Workweek by the Numbers
| Metric | Value | Source |
|---|---|---|
| Companies keeping four-day week after six-month trial | 90% | Nature Human Behaviour, 2025 |
| Employees / organizations in largest peer-reviewed trial | 2,896 / 141 | Nature Human Behaviour, 2025 |
| Burnout change (five-point scale) | -0.44 | Nature Human Behaviour, 2025 |
| Job satisfaction change (ten-point scale) | +0.52 | Nature Human Behaviour, 2025 |
| UK 2022 pilot companies continuing | 56 of 61 (92%) | Autonomy, 2023 |
| UK 2022 pilot staff turnover change | -57% | Autonomy, 2023 |
| UK 2022 pilot revenue vs. comparable prior periods | +35% | Autonomy, 2023 |
| UK 2022 staff reporting reduced burnout | 71% | Autonomy, 2023 |
| US / Ireland pilot revenue over the trial | +8% | 4 Day Week Global, 2022 |
| US pilot employees wanting to continue | 95% | 4 Day Week Global, 2023 |
| UK 2025 Foundation pilot firms retaining the model | 17 of 17 (100%) | 4 Day Week Foundation, 2025 |
| UK permanently accredited four-day employers | 200+ | 4 Day Week Foundation, 2025 |
| US employers offering a four-day week (2024 vs. 2022) | 22% vs. 14% | APA, 2024 |
| US full-time employees actually working four days | 8% | Gallup, 2022 |
| US workers supporting a four-day week | 81% | Bankrate, 2023 |
| Believe they would be happier and equally productive | ~80% | APA, 2024 |
| German orgs continuing reduced hours (two-year follow-up) | 70% | 4 Day Week Global, 2026 |
| Icelandic workforce on shorter or entitled hours (2021) | 86% | Alda and Autonomy, 2021 |
| Portugal companies reporting a performance rise | 85% | Birkbeck and Henley, 2024 |
| Tokyo metropolitan government four-day option | Launched April 2025 | Tokyo Metropolitan Government |
Methodology and Sources
Data was gathered by aggregating figures directly from primary pilot reports, peer-reviewed research, government announcements, and named survey publishers, tracing every trade-press mention back to its originating source before inclusion.
- 4 Day Week Global — UK, US and Ireland, Germany, and Portugal pilot programme results (2022 to 2026)
- The Autonomy Institute — The Results Are In: The UK’s Four-Day Week Pilot (2023)
- 4 Day Week Foundation — employer accreditation scheme and 2025 UK pilot results (2025)
- Wen Fan and Juliet Schor et al., Nature Human Behaviour — Work time reduction via a 4-day workweek finds improvements in workers’ well-being (2025)
- Gallup — Is the 4-Day Work Week a Good Idea? (2022)
- American Psychological Association — 2024 Work in America Survey (2025)
- Bankrate — flexible-work and four-day-week worker survey (2023)
- Gartner — future-of-work research on four-day schedules (2024)
- 4dayweek.io — four-day-week job board and company registry data (2026)
- Birkbeck, University of London and Henley Business School — Portugal four-day-week pilot (2024)
- Exos, via CNBC — internal four-day-week retention results (2024)
- Alda and The Autonomy Institute — Icelandic four-day-week trials (2021)
- Tokyo Metropolitan Government, via NBC News — four-day-week option for employees (2024 to 2025)
Data watch: 4 Day Week Global and the 4 Day Week Foundation run rolling pilot cohorts, with new UK and international results expected across 2026; Gallup’s workplace engagement research and the APA Work in America Survey both refresh annually, with the next APA edition expected in H2 2026; Germany’s two-year follow-up (published February 2026) is the most recent longitudinal read, and additional national pilots in Spain, Portugal, and Japan are due to report through 2027.
Last updated: July 17, 2026.
We review and update this page quarterly as new data is published.