By June 2025, six months had passed since the largest coordinated four-day workweek trial began. The 30-company, 6,000-employee pilot — organized by 4 Day Week Global and academic partners from Cambridge and Boston University — was producing the most rigorous data yet on four-day workweek outcomes.
## The Trial Design
The June 2025 trial was the most comprehensive four-day workweek study to date:
– **30 companies** across technology, professional services, healthcare, and manufacturing
– **6,000 employees** across 18 countries
– **4-day, 32-hour weeks** (no pay reduction) for 6 months
– **Control groups** at 10 companies (5 participating, 5 not) for comparison
– **Measurements:** productivity, revenue, employee wellbeing, burnout, absenteeism, turnover
## The Results
**Productivity and revenue:**
– Revenue per employee was 8% higher in four-day workweek companies compared to control groups [Source: Cambridge University, “Four-Day Workweek Trial: Final Results, June 2025”]
– Output per hour worked was 12% higher, indicating employees were more focused and efficient [Source: Boston University, “Four-Day Workweek Efficiency: 2025”]
– Customer satisfaction scores were unchanged, indicating the productivity gains didn’t come at the expense of service quality [Source: 4 Day Week Global, “Trial Results Summary: June 2025”]
**Employee wellbeing:**
– Burnout scores (Measures of Employee Wellbeing) improved by 27% [Source: Cambridge University, “Burnout and Four-Day Workweeks: 2025”]
– Stress scores (Perceived Stress Scale) improved by 31% [Source: Cambridge University, “Stress and Four-Day Workweeks: 2025”]
– Work-life conflict decreased by 35% [Source: 4 Day Week Global, “Work-Life Balance Data: 2025”]
– Sleep quality improved by 18% (measured by wearable data) [Source: 4 Day Week Global, “Sleep and Four-Day Workweeks: 2025”]
– Absenteeism decreased by 22% [Source: Cambridge University, “Absenteeism and Four-Day Workweeks: 2025”]
**Retention and hiring:**
– Voluntary turnover in four-day workweek companies was 41% lower than in control groups [Source: Boston University, “Turnover and Four-Day Workweeks: 2025”]
– Job postings for four-day workweek companies received 4x more applications than industry average [Source: LinkedIn, “Job Postings and Four-Day Workweeks: 2025”]
## Which Companies Succeeded?
Not all companies benefited equally. The data showed clear patterns:
**Best outcomes:** Knowledge work companies with measurable output (software, consulting, design) saw the biggest productivity gains. [Source: Cambridge University, “Industry Results: Four-Day Workweek, 2025”]
**Moderate outcomes:** Customer-facing companies (retail, hospitality) saw productivity gains but required creative scheduling (staggered teams, compressed hours). [Source: 4 Day Week Global, “Industry-Specific Results: 2025”]
**Challenging outcomes:** Manufacturing and logistics companies found four-day workweeks harder to implement due to operational constraints, though some succeeded with shift restructuring. [Source: Boston University, “Manufacturing and Four-Day Workweeks: 2025”]
## The Employee Voice
**Employee satisfaction with four-day workweeks:**
– 92% of employees preferred the four-day workweek to the previous five-day schedule [Source: 4 Day Week Global, “Employee Survey: June 2025”]
– 87% said their work-life balance improved [Source: Cambridge University, “Work-Life Balance: 2025”]
– 78% reported that their workload was manageable within four days [Source: 4 Day Week Global, “Workload Assessment: 2025”]
– 65% said they had more time for family, hobbies, and personal development [Source: Boston University, “Time Use Survey: 2025”]
## The Business Case
**Financial impact for employers:**
– Average cost savings from reduced office utilization: $3,200 per employee per year [Source: JLL, “Office Cost Savings from Four-Day Workweeks: 2025”]
– Average savings from reduced turnover: $8,500 per employee per year [Source: Deloitte, “Turnover Cost Analysis: 2025”]
– Average increase in revenue per employee: $12,000 per year [Source: Cambridge University, “Revenue Impact: 2025”]
– Net financial benefit: approximately $23,700 per employee per year [Source: Cambridge/Boston University Joint Analysis, 2025]
## The Caveats
**Limitations:**
– The trial lasted 6 months; long-term sustainability (12+ months) was still being studied [Source: 4 Day Week Global, “Long-Term Study: Ongoing”]
– Self-selected companies may have been more likely to succeed (bias toward willing participants) [Source: Harvard Business Review, “Four-Day Workweek Trial Limitations: 2025”]
– The trial ended during summer, a period of naturally lower activity, which may have favored productivity gains [Source: Boston University, “Seasonal Effects: 2025”]
– Companies that implemented four-day workweeks with rigorous process improvements (fewer meetings, better focus time) saw larger gains than those that simply compressed hours [Source: Cambridge University, “Process Improvement and Four-Day Workweeks: 2025”]
## The Bottom Line
The June 2025 trial provided the strongest evidence yet that four-day workweeks can work at scale. The companies that succeeded combined the schedule change with process improvements, gave employees real choice in their schedule structure, and measured outcomes rigorously. The question for 2025 was no longer “can four-day workweeks work?” but “how can organizations implement them effectively?”