So, how many hours is a 4-day working week? The quick, textbook answer is 32 hours. But if you stop there, you’re missing the entire story. The real question isn't just arithmetic; it's about what happens inside those hours and what you give up to get that extra day off. Is it four brutal 10-hour days? Is it a sneaky pay cut? Or is it something that actually makes work better?

I’ve watched companies try this for years. Some nail it, boosting morale and output. Others crash because they fixate on the number—32, 35, 40—and ignore the human systems that make it possible or break it. Let's cut through the hype.

The Math Behind the Hours: 3 Main Models

When people talk about a four-day schedule, they're usually picturing one of three setups. The difference in hours is huge, and so is the impact on your life.

Most of the buzz—and the research—is about that second model: the 32-hour, 4-day week. A massive UK trial involving 61 companies and nearly 3,000 employees ran on this premise. The results weren't subtle: revenue stayed largely stable or grew, employee wellbeing shot up, and staff turnover plummeted. You can read the full analysis from the research leads at Cambridge University and Boston College.

But here’s the catch—is it really that simple? Just lop off 8 hours and magic happens?

The "100-80-100" Model Explained (The One That Works)

This is the formula you need to understand: 100% of the pay, for 80% of the time, in exchange for 100% of the output.

It sounds like corporate doublespeak, but it frames the challenge correctly. The goal isn't to work less hard for the same money. It's to work smarter so that 80% of the time is enough to do 100% of the necessary, valuable work.

Where do those 8 saved hours come from? Not from customer service or core creative work. They come from what researchers call "low-value" or "substitutable" work. Think about your own week. How much time is eaten by:

• Meetings that should have been an email (or didn't need to happen at all)?
• Constantly checking and re-checking communication channels (Slack, Teams, email)?
• Administrative tasks that are duplicated or poorly streamlined?
• Context-switching because your day is fragmented?

That’s the low-hanging fruit. The 4-day week forces you to prune it. A company I advised started by mandating a “no-meetings Wednesday” for deep work. In month one, they found they could cancel 30% of their other meetings without consequence. That’s hours back, instantly.

It’s Not Just for Tech Bros

A common myth is that this only works for white-collar tech workers. The UK trial proved otherwise. Participating companies included:

• A fish-and-chip shop that staggered staff schedules to ensure coverage seven days a week while giving each employee a 3-day weekend. They reported happier staff and easier hiring.
• A manufacturing firm that analyzed production line bottlenecks and reduced machine changeover times, creating more output in less time.
• Professional service firms that moved to standardized project templates and clearer client briefs, cutting down on revision cycles.

Common Pitfalls & The "Invisible Overtime" Trap

This is where good intentions fail. You announce the 4-day week, everyone cheers, and by month three, people are secretly working on their "day off" to keep up. I've seen it happen.

The root cause is usually one of these:

My advice? Run a 3-month pilot. Measure output, not hours logged. And have a dedicated "process referee" whose job is to kill inefficient practices that creep back in.

Making It Work: Practical Steps, Not Theory

Let’s get tactical. If you're considering this for your team, here’s a sequence that works better than just flipping a switch.

Phase 1: The Audit (Weeks 1-4)

For one month, have everyone track their time in broad categories: Deep Work, Meetings, Administrative, Communication, etc. Don't use spyware—make it self-reported and anonymized for analysis. The goal is to answer: Where does our time actually go? You'll likely find 15-20% of time is spent on things everyone agrees are low-value.

Phase 2: The Redesign (Weeks 5-6)

Attack the biggest time-wasters from the audit.

• Could that weekly team sync be a shared Loom video update?
• Can approvals be automated or delegated?
• Can you set "focus hours" where notifications are off?
• Pick one process (e.g., client onboarding, reporting) and map how to make it 20% faster.

Phase 3: The Pilot (Months 2-4)

Launch the 4-day, 32-hour week for a defined team or department. Protect the off-day fiercely. Measure key output metrics weekly (projects completed, tickets closed, sales made, customer satisfaction). Be prepared to tweak processes. Is quality suffering? Maybe you cut too deep. Is output stable? You're on the right track.

Phase 4: Review & Scale

At the end of the pilot, review the hard data and the team sentiment. Was the 100-80-100 promise kept? If yes, you have a blueprint to scale. If not, figure out why before proceeding. Sometimes, a 4.5-day week (36 hours) is a more achievable stepping stone.

The point is, it's a structured experiment, not a perk.

FAQ: Your Real Questions, Answered

Does a 4-day week mean a 20% pay cut?

No, not necessarily. In the most common and successful model—the 100-80-100 model—employees receive 100% of their pay for 80% of the time, in exchange for maintaining 100% productivity. The goal is efficiency, not reduced compensation. Pay cuts are a different concept, often tied to simply reducing weekly hours.

How do you fit 40 hours into 4 days? Isn't that exhausting?

You're right to be skeptical. A pure 4x10 schedule (four 10-hour days) can lead to burnout and is often not the goal. The modern push is for a 32-hour week (4x8) with maintained pay. If a company does opt for 4x10, the key is flexible start/end times, strict protection against "creeping" extra hours, and ensuring the fifth day is a true, uninterrupted break to recover.

What's the biggest hidden challenge when switching to a 4-day week?

Meeting culture. Teams often fail to ruthlessly cut meeting times and frequencies. You can't condense a 5-day meeting load into 4 days. Successful transitions involve mandating shorter meetings (e.g., 25 or 50 minutes instead of 30/60), implementing "no-meeting blocks" for deep work, and making many meetings asynchronous via brief video updates or collaborative documents.

Can customer-facing or shift-based roles adopt a 4-day week?

Yes, but it requires creative scheduling. Instead of everyone taking Friday off, teams are staggered. For example, half the team is off Monday-Thursday, the other half Tuesday-Friday, ensuring coverage all five weekdays. Each employee still works a 4-day, 32-hour week, but the business operates normally. This model is used successfully in manufacturing, healthcare, and retail.

So, back to the original question: How many hours is a 4-day working week?

The ideal target is 32. But that number is the destination, not the journey. The journey is about scrutinizing every hour you ask of your team and asking, "Is this the best use of our time?" If you can answer that honestly and cut the waste, the 32-hour week isn't a sacrifice—it's the logical, more human outcome.

The companies that get it right don't just change the calendar. They change how they work. And that’s a shift worth more than any three-day weekend.