How Many Working Weeks Are in a Year in the UK? A simple guide.

• Not all weeks are equal; it's more than just annual leave. Bank holidays, and absences also reduce the actual working weeks in a year.
• You can reduce bottlenecks at busy periods and avoid burning out employees by correctly estimating your staff's availability.
• Individual circumstances, part-time schedules, and regional differences mean working weeks vary. Using HR tools like Leave Dates, you can plan with real data, not assumptions.

Stop us if this sounds familiar: you’re trying to plan the next big project, forecast capacity, or even just work out how many cheeky long weekends you can squeeze in this year if you stack your leave. You ask yourself what you thought was a simple question – ‘how many working weeks are in a year?’ – but find your eyes boggling at an increasingly complex spreadsheet as you try and take account of leap years, regional bank holidays and pro rata leave entitlements.

The answer is not 52. If only life were that simple. But even though there’s never a week when no one is working, not every week is a ‘working week’.

For employees and, crucially, UK business owners and managers who need accurate staffing and resource plans, the true number of working weeks is probably somewhere between 44 and 47.

Erm… where did all those other weeks go? Well, for better or worse (better!), humans are not machines. We need time off or we break down (and are less easily fixed when we do). We have this thing called bank holidays. We even – shock horror – get sick. This makes us less predictable than machines, but much more lovable. For various reasons, we don’t (and can’t, and shouldn’t) work every week. Some businesses aren’t operational part of the year, or have fluctuating staff levels to account for seasonal shifts in demand (have you ever been to Santa’s grotto in April? Not a vibe).

As you can begin to see, answering this question is less of a maths challenge and more of a logic puzzle.

Knowing how many weeks are in a working year is the bedrock of smart resource management. It means employees can plan out their leave to avoid two dreaded Bs – bottlenecks and burnout, and managers can plan ahead. It’s key to managing workload at the business, team, and personal levels. It is also relevant to calculating – and planning – annual leave.

So let’s crunch some numbers.

At the headline level we have 52 weeks in a year, and a standard working week of 5 days. Add in 8–10 bank holidays, depending on where in the UK you live, plus 28 days’ statutory annual leave (around 5 working weeks), and we’re looking at around 47… ish.

If your payroll software doesn’t accept ‘ish’ as a valid numerical input, you’re going to need some info specific to your company/employees. The number of working weeks will be slightly different for every employee, and this also has an impact on the number of working weeks for the business – these numbers won’t be the same, but we need to know what they all are if we’re going to get resource planning and leave entitlements right.

At an individual employee level, you first need to know how many working days are in your company’s year. For a typical 9–5, Monday to Friday worker, a 365-day year has 260 potential working days. Due to handy laws that forbid enslavement and overwork, you don’t have to work all of those and we can start knocking some numbers off that starting total…

First up, annual leave. The statutory minimum for a full-time employee is 5.6 weeks (28 days of your typical 9–5), which means 260 days becomes 232. So far, so simple.

Up next is bank holidays – potentially. You need to find out if these are included within annual leave, or on top. If they’re included, your total stays the same. If they’re not, you then need to find out where you live and what year it is. This is because bank holidays are regional and vary depending on which country in the UK you’re in, and some of them fall on different days of the week each year. On average, England has 8 bank holidays (1.6 working weeks) per year so we’ll use that for the purpose of our calculations here.

We’re nearly there now, but we have one more factor to consider – and it’s a biggie: life. Nobody can make it through a full working year without a sickie, an emergency, or a wellbeing day – and there are no prizes if you do. Businesses might be planned on paper but they’re operated in the real world, and so effective resource planning needs to account for sickness and absence. It could be parental leave, compassionate leave, training days – there are a whole host of perfectly valid reasons an employee might not be ‘working’ for a few days.

The ONS gives an average number of sick days per UK employee of 4.4 a year. So we can conservatively take off another 5 days (1.0 working weeks) per year for absence for our – very healthy, highly trained and childless! – employee.

Once we’ve accounted for all the time that someone could legally and reasonably be away from their desk, we have a more realistic picture of what the true number of working weeks in a year is:

52 – 5.6 weeks annual leave – 1.6 weeks bank hols – 1.0 week absence = 43.8

This means that, though there are 52 weeks in a year, your average full-time employee will have about 44 working weeks. That’s in a best-case scenario, presuming there is no parental leave or other extended statutory leave taken, or long-term sickness.

If you’re a small business owner or HR manager, that 44-week figure is a critical business metric. If you planned your staffing and budget around 52 weeks, you’d be inflating your capacity by 15% – a huge margin. If you lost 15% of orders, or faced an increase of 15% in costs, or missed 15% of your deadlines, you’d be seriously worried. It’s a big error, so it’s crucial you get this number right.

For some businesses, it might be more helpful to calculate how many working days in a year, or even hours, for a more precise metric. You can then work backwards from that to get your working weeks.

In our above scenario, taking off annual leave, bank holidays and sickness/absence, we’re left with 219 working days. This is your actual maximum potential capacity per employee, not the 253 potential working days in each year – you have to assume (and enforce) all your staff will take all their annual leave, so there is simply no point factoring those days into your resource planning.

There are 253 potential working days in the year. A small business has 10 full-time employees with 28 days’ leave, which includes bank holidays. For 10 people, that means 280 days of leave per year. Adding in 5 sick/training days per year for each person, we lose another 50 days per year.

If we don’t factor in leave and absence, it looks like a team of 10 gives us a capacity of 2,530 working days per year, or 506 working weeks. When we take those days off – which we should, because they are almost certain to be used – we actually have a capacity of 2,200 working days, or 440 working weeks for our business (44 per member of staff).

If we based our business’ capacity on the assumption of 52 weeks a year (520 collective working weeks), we’d be overstating it by 80 weeks. That’s eight full-time employees for 10 weeks of the year. And that’s assuming no extended absence beyond the statutory and the average. When you look at it like that, it’s easy to see how projects run over, deadlines are missed, and people burn out.

A figure of 44 working weeks per employee, per year is a far more accurate, realistic, and healthy starting point when planning your targets, budgets, and capacity.

Of course, while Monday to Friday 9–5 might historically be the ‘norm’, today it’s anything but. Part-time and flexible work are increasingly common, and many people work irregular hours. Yet all workers are entitled to 5.6 weeks’ paid annual leave. For part-timers, this is worked out pro rata (eg 3 days a week = 16.8 days’ paid leave). For workers with irregular hours, as of 1 April 2024 holiday entitlement is calculated at a 12.07% accrual rate based on hours worked in a pay period.

There is no simple or static answer to the question, “How many working weeks in a year?” It changes based on the year, the region, the contract, the employee and the employer. So the key is not to land on a single number, but to have a smart system that can calculate your actual capacity, in real time. In this context, leave management software becomes an essential tool for small businesses and HR teams, reporting on actual available capacity per team taking all leave into account and automatically applying bank holiday schedules.

When you can get your head around the actual number of working weeks in a year, for your staff and for the business, you’ll never overestimate your capacity and set yourself up for failure. You’ll have happy customers, happy staff, and happy HR and can feel safe in the knowledge that your most precious resource – your staff’s working hours – is completely visible and well-managed. No nasty surprises here!