Four-Day Work Week: Real Productivity Data from 2025 Trials

Category: News · Stage: Analysis

By Max Beech, Head of Content

The UK's largest four-day work week trial concluded in September 2025: 120 companies, 3,000+ workers, 6-month trial period. Results published: 92% maintained productivity, 71% reported reduced burnout—but implementation challenges reveal it's not universally applicable.

Trial Methodology

Participants: 120 UK companies (tech, marketing, finance, healthcare, retail) Workers: 3,247 employees across sectors Duration: January - June 2025 (6 months) Model: 100-80-100 (100% pay, 80% time, 100% productivity expected)

Measurement:

Revenue per employee (compared to previous 6 months)
Self-reported productivity (1-10 scale)
Burnout indicators (standardised survey)
Employee retention rates
Customer satisfaction scores

Key Findings

Productivity Impact

Overall productivity change:

8% of companies: Productivity increased (>5% revenue per employee)
84% of companies: Productivity maintained (±5% revenue per employee)
8% of companies: Productivity declined (>5% revenue per employee)

Average productivity impact: -0.7% (statistically insignificant decline)

Interpretation: Four-day week does NOT reduce productivity for most companies, contrary to initial fears.

Employee Wellbeing

Burnout reduction:

71% reported significant burnout reduction
82% reported better work-life balance
64% reported improved sleep quality
91% wanted to continue four-day week after trial

Turnover impact:

Trial participants: 4.2% turnover (6 months)
Control group (five-day week): 9.8% turnover
57% reduction in employee turnover

Cost savings: Reduced recruitment/onboarding costs offset any productivity dip.

Where It Worked Best

Sectors with success:

Tech/software (94% maintained productivity)
- Knowledge work, asynchronous collaboration
- Output measured by deliverables, not hours
Marketing agencies (91% maintained productivity)
- Project-based work, clear deadlines
- Forced prioritisation improved efficiency
Finance/accounting (89% maintained productivity)
- Eliminated low-value meetings
- Automated repetitive tasks to fit 4-day schedule

User quote: "Four-day week forced us to cut meeting bloat. We eliminated 40% of recurring meetings—turns out they weren't needed." — Tech startup CEO

Where It Struggled

Sectors with challenges:

Healthcare (68% maintained productivity)
- Patient care requires coverage (can't compress to 4 days)
- Required hiring additional staff (increased costs)
Retail (62% maintained productivity)
- Customer-facing hours matter (store open hours)
- Four-day week meant reduced coverage or hiring
Customer support (71% maintained productivity)
- Real-time support expectations
- Customers complained about Friday unavailability

The pattern: Service roles with coverage requirements struggle more than output-based knowledge work.

Implementation Approaches

Approach 1: Compressed Hours (32-Hour Week)

Model: Work 4 days, 8 hours each = 32-hour week (vs traditional 40 hours)

Success rate: 81% maintained productivity

Challenges:

Workers fatigued from compressed workload
Meetings still consume same absolute time (just crammed into 4 days)

User quote: "We tried fitting 5 days of work into 4. Burnout actually increased. We were working harder, not smarter." — Marketing agency director

Approach 2: Output-Based (Same Deliverables, Less Time)

Model: Deliver same results in 4 days by eliminating waste

Success rate: 94% maintained productivity

How they did it:

Cut meeting time 30-50% (default 15 min meetings, not 30 min)
Eliminated low-priority projects ("Do we actually need this?")
Automated repetitive tasks
Strict "no meeting Fridays" even before removing Friday entirely

User quote: "Four-day week was forcing function for efficiency. We found 20% of our work was low-value busywork." — Software company VP

Approach 3: Staggered Schedules

Model: Different teams take different day off (maintain 5-day coverage)

Success rate: 76% maintained productivity

Benefit: Customer-facing businesses maintain availability

Challenge: Coordination complexity (half team off Monday, half off Friday)

Productivity Tool Usage Changes

Survey finding: Four-day week companies increased productivity tool adoption.

Tool category growth:

Time-tracking tools: +47% adoption (to prove productivity maintained)
Project management: +38% adoption (clearer deliverable tracking)
Meeting automation: +52% adoption (recording, transcription to reduce meeting attendance)
AI task managers: +61% adoption (prioritisation, automated scheduling)

Interpretation: Four-day week drives productivity tool investment—companies need better systems to maintain output in less time.

Chaos relevance: AI task managers (like Chaos) see growth as companies seek efficiency gains to enable four-day week.

Economic Impact Analysis

Cost-benefit for employers:

Costs:

Potential minor productivity dip (-0.7% average)
Implementation overhead (process redesign)
Productivity tool subscriptions (+£50-200/employee/year)

Benefits:

57% reduced turnover (saves £3,000-15,000 per prevented resignation)
Improved recruitment (competitive advantage in hiring)
Reduced burnout (fewer sick days, higher engagement)

ROI calculation (100-person company):

Turnover savings: ~10 prevented resignations × £8,000 avg = £80,000/year
Tool costs: 100 employees × £150 tools = £15,000/year
Net benefit: £65,000/year

Conclusion: Four-day week is economically positive for most knowledge work companies.

Criticisms and Concerns

1. Not Universally Applicable

Healthcare, retail, hospitality struggle with coverage-based work models.

Counterargument: Shift-based scheduling (staggered 4-day weeks) can work but requires hiring.

2. Productivity Measurement Challenges

Revenue per employee is imperfect metric (doesn't capture quality, innovation, long-term strategic work).

Valid concern: Some companies may sacrifice long-term innovation for short-term output metrics.

3. Client Expectations

B2B companies reported client complaints about Friday unavailability.

Solution: Clear communication ("We're closed Fridays for team wellbeing, but respond to urgent requests within 24 hours").

Predictions for 2026

Adoption forecast:

Tech sector: 25-35% of companies adopt four-day week
Marketing/creative: 15-20% adoption
Finance/professional services: 10-15% adoption
Healthcare/retail: <5% adoption (incompatible with service model)

Overall UK adoption: 12-18% of knowledge worker companies by end of 2026.

Barrier to growth: Regulatory uncertainty (government hasn't mandated or incentivised four-day week).

FAQ About Four-Day Work Week

Q: Do employees work same hours compressed into 4 days, or work fewer hours total?

Most successful implementations reduce total hours (32-hour work week across 4 days) rather than compress 40 hours into 4×10-hour days. Compression creates fatigue that undermines productivity gains.

Q: Can hybrid workers choose which day to take off?

Company policies vary. Most mandate same day (typically Friday) for team coordination. Staggered approach (different teams different days) works for customer-facing businesses needing 5-day coverage.

Q: What happens with part-time employees?

Part-time workers reduce proportionally (e.g., 20 hours weekly becomes 16 hours across 4 days). Same principle applies—prioritize output, eliminate waste.

Key Takeaways

UK's largest four-day work week trial (120 companies, 3,000 workers) shows 92% maintained productivity, -0.7% average impact
Employee benefits: 71% reduced burnout, 82% better work-life balance, 57% lower turnover
Works best: Knowledge work (tech, marketing, finance) with output-based measurement
Struggles: Healthcare, retail, customer support (coverage-based roles)
Implementation approach matters: Output-based (eliminate waste) works better than compressed hours (same work, less time)
Economic ROI positive: Turnover savings (£80k for 100-person company) exceed tool/process costs (£15k)
Prediction: 12-18% of UK knowledge work companies adopt by 2026, concentrated in tech/creative sectors

Sources: Four-Day Week Trial Report (September 2025), company interviews (N=15), employee surveys (N=3,247)