Calculating working hours

Calculating working hours

Calculating working hours correctly is extremely important. There are many rules and regulations, for various industries, with regards to the maximum working week. This subject is so important that the UK government has currently committed to retaining EU working practices, in light of Brexit, with regards to maximum working hours.

Why might you need to be calculating working hours?

There are numerous scenarios where employees have been placed under pressure by their employers. This may relate to official breaks, activities undertaken and most commonly hours worked per week. It is very important to monitor your hours per week in relation to working time regulations. You might need to calculate your working week if:-

  • You suspect your working week has crept above 48 hours
  • You have received a request from your employer to work more than 48 hours a week
  • You have been asked to opt-out of the “Working Time Regulations

We will now take a look at the three-step approach to checking your working hours and whether your employer is abiding by “Working Time Regulations”.

Does the 48-hour working week time limit apply to you?

There are some situations where a maximum 48-hour week is applicable and there are some scenarios which are exempt from the regulations. Those which are exempt include:-

  • Lorry, coach or heavy goods vehicle drivers
  • Workers on a ship
  • Domestic servants in a private household
  • Armed forces, emergency services and police
  • Senior management/executives
  • Airline staff, cabin crews and pilots

This list is by no means exclusive but it does give you an idea of some of the more common scenarios exempt from the working time regulations. When it comes to senior management/executives, they are exempt because their time is not measured. Due to their position in the company, they may need to be available to take various actions/decisions on a continual basis.

There will be occasions where you may work in excess of 48 hours in one week but less than 48 hours the next week. It is important to note that the 48-hour limit is an average over a 17 week period. Interestingly, the working time regulations supersede any clause in your contract which may “force you” to work more hours than the average weekly limit. As we covered in one of our earlier articles, it matters not whether your contract is written or verbal, the same protection still applies.

Opting out of the working time regulations

While the working time regulations are there to protect employees, all employees have the option of opting out of these regulations. This effectively leaves them free to work in excess of an average 48 hours per week, measured over a 17 week time period. The majority of employers will ask you to sign an agreement if you wish to opt-out of the regulations. However, at any time you can cancel this arrangement.

The notice period to cancel your opt-out arrangement is a standard seven days, in writing. However, there are situations where an employer may require additional notice. This will be written into your contract and can be anything up to 3 months. It is important to note that you cannot be disadvantaged by your employer because you decided to cancel your opt-out arrangement. Once your notice period has finished, you will not be forced/expected to work in excess of an average 48 hours a week.

When it comes to remuneration there are two issues to take into consideration:-

  • Those paid on an hourly rate will see a reduction in their income
  • Those who receive a fixed remuneration will likely see a reduction to reflect their reduced hours

This is only fair because employees have protection from extended working hours, which has to be reflected in remuneration paid by the employer.

What counts towards the calculation of your working week?

Even though we have contracts, HR departments and the Internet, many people are still unaware of exactly what is included when calculating working hours for their working week. In simple terms, this calculation is made up of the working hours per week you have agreed with your employer. If by choice you decided to do additional work, this would not normally be taken into account. We also have the traditional rest breaks and time taken off work which is not included. If you are working, and it was pre-arranged, the time would normally be included.

Travel time

When does travel time count towards your working week and when is it excluded? This is the answer in bullet point form:-

  • Travelling as part of your work, i.e. sales rep, is included when calculating your working week
  • Where you travel from property to property, i.e. a care worker, this time should also be included as part of your working week
  • Simply travelling to the same working location each day, this travel time is not eligible when working out your hours

The treatment of travel time is a relatively straightforward subject, but one which often needs simplifying.

Job-related training

In simple terms, any job-related training arranged with your employer will count towards your working week. Any training which you carry out on your own volition would not normally count towards your working week. There are also additional details to take into account:-

  • Additional employer authorised training, no matter who covers the expense, will count towards your working week
  • Contracted training, outside of your normal working hours, will also count towards your working week

There are occasions where employees may decide to undertake additional training during their own time, and at their own expense. In some scenarios, employers may offer financial assistance but these hours would not normally be included in your working week summary.

Working lunches and statutory breaks

Many professions involve a number of working lunches, taking in formal and informal discussions. The difference between lunch and a working lunch is simple; you are doing prearranged work on behalf of your employer. So the scenarios to consider include:-

  • Client lunches count as working hours
  • Lunch breaks, when no work is carried out, do not count
  • Voluntary “working lunches” do not count towards your weekly hours
  • Statutory rest periods and breaks between shifts don’t count

The only real point of confusion with regards to working lunches is whether they were prearranged or voluntary. The regulations only require your employer to include additional time in your working hours if they were prearranged. You may be able to request a “working lunch” where time is of the essence or you are assisting colleagues.


When it comes to calculating working hours including overtime there are two issues to consider before we look at the various scenarios:-

  • Overtime is classed as work hours above and beyond your contracted hours
  • You can only work overtime if your contract stipulates this

There are two basic types of overtime:-

  • Voluntary, not prearranged with your employer, which is classed as unpaid
  • Prearranged overtime is classed as paid overtime and counts towards your working week

The term “voluntary overtime” is more commonly associated with those who stay behind, beyond their contracted hours, to finish some work. Where the work is time critical, and could not wait until the next working day, it may be sensible to broach the subject with your employer.


The subject of on-call remuneration is one of the more complicated when it comes to calculating working hours. It is important to note that you are not obliged to be on call/on standby if this is not in your contract. Where it is in your contract, there are two specific types of on-call which are those based on working premises and those in a social setting.

Work-based premises

When looking at work-based premises for on-call employees, it matters not whether you are called out or whether you remain on the premises for the duration of your shift.

  • If you need to stay on work premises while being on call, all hours will count towards your working week tally.
  • If you are asked to stay within for example 5 minutes of your workplace, all of the time will typically count towards your working week
  • If you are on work premises and asleep, awaiting outcalls, even your sleep time will count towards your working week

In essence, if your movement is restricted to your workplace (or the immediate area) then all of the hours that you spend on call are “working hours”.

Home-based settings:-

The strict definition of “home-based settings” is as follows:-

  • If you can carry out none work-based activities, or even sleep, time spent at home does not count towards your weekly total.

That said, from the moment you are called out for work reasons, to the moment you return, these hours will count towards your weekly total. There is a clear definition between working hours and leisure hours, even if you are on call.

Working from home

In recent times we have seen more employers giving employees the option to work from home or mix home/office settings. When it comes to remuneration and working hours for those working from home, this is relatively straightforward:-

  • If time spent working at home has been prearranged with your employer, this will count as part of your working week
  • If you voluntarily do work from home, this will not normally count towards your working week

There are also a couple of other issues to take into account where an employee will voluntarily work from home. Some employers may not allow work-related data to be used outside of the office environment, often for security reasons. On occasion, although not legally obliged to, some employers will recognise additional work carried out at home by their employees. If you are planning any additional work from home, it is advisable to speak with your employer beforehand.

Working at night

There are specific regulations for those employed during the “normal” working day and those who work at night time. The definition of a night worker is someone who regularly works “at least three hours” at night. There is some room for manoeuvre when it comes to contracts:-

  • Some employers may use a slightly different definition for night time hours
  • If there is no definition in your contract, the default position is between 11 PM and 6 AM
  • As a minimum, any contracted hours between midnight and 5 AM are legally classed as night hours (even if your contract says otherwise)

The regulations regarding working at night are strict. You cannot work more than an average of eight hours during a 24-hour period. This average figure is again calculated using a 17 week period. While those who traditionally work in the daytime can opt-out of working time regulations, this is not an option for those who work at night. There are some broad exceptions to the rule, which we highlighted earlier in this article, but these exceptions are few and far between.

Time spent away from work

There are various legal obligations with regards to public holidays, paid holidays and other types of leave. However, when it comes to calculating your working week, you can’t include:-

  • Sick leave
  • Paid annual leave
  • Maternity leave
  • Paternity leave
  • Adoption leave
  • Unpaid leave (such as a gap year)

Basically, if you are not available to work then these hours should not be included in your working week. You may find that with some employers you are legally contracted to take your full paid annual leave each year. Ironically, employers tend to become aware of working/client issues, and even fraud, during the time that some employees are away from the workplace.

How to calculate working hours

Once you have all of the data, it is time to calculate your working hours. There are two figures to focus on when calculating your working hours, 48-hour maximum working week and the 17 week period over which your average working hours are calculated. In this scenario we will assume that:-

  • You are contracted to work 45 hours a week
  • For seven weeks of a 17 week period, you work seven hours overtime per week

Calculate contracted hours over 17 week period:-

45 hours per week x 17 weeks = 765 hours

Calculate overtime hours over 17 week period:-

7 hours per week x 7 weeks = 49 hours

Average weekly hours

(765 hours + 49 hours) divided by 17 weeks = 47.9 hours per week

This figure is under the maximum 48-hour working week and is therefore lawful.

However, if you had worked eight hours overtime for seven weeks this would increase the overtime element to 56 hours. As a consequence, your average hours per week would have been 48.3 hours – over the legal limit. Obviously, where you had agreed to opt out from working time regulations this would have no legal bearing.

How to calculate night time working hours

While the 48-hour week for a traditional employee is fairly easy to calculate, there is a slight difference when it comes to those working at night. For those working night time hours, they are not legally allowed to work more than on average eight hours a day, over a 17 week period. The calculation is a little more difficult, as follows:-

  • You work 4 shifts of 12 hours each week
  • You are entitled to a mandatory one rest day each week

Calculated over a 17 week period, the number of hours worked is as follows:-

4 shifts x 12 hours = 48 hours per week
17 x 48 hours = 816 hours over a 17 week period

Number of working days over a 17 week period:-

17 weeks x 7 days = 119 days
1 rest day per week = 17 days

Therefore the maximum number of working days over a 17 week period is 102 days. If we divide the total hours worked by the maximum days the average working day is as follows:-

816 hours/102 days = an average of 8 hours per working day

This is within the legal limits for night-time work. However, if there had been 5 shifts of 10 hours each week this would exceed the legal limit:-

850 hours/102 days = 8.3 hours per day

When you see these figures before you, they are common sense and relatively simple to calculate, but how many of us actually calculate our average weekly hours? If you are not aware of your average weekly hours then you have no idea whether your employer is operating within the current regulations.

There have been numerous instances where employers have placed employees under pressure to work excessive hours. In some cases, this can lead to physical and mental exhaustion and unfortunately accidents in the workplace. If these accidents occur as a consequence of negligence by your employer, you may have a case for claiming personal injury compensation.


Unfortunately, while many of us are aware of the rules and regulations regarding employment and employers, the majority of us are led merrily by the hand of our employers. It is important to be aware of your working hours, how the average is calculated and the legal obligations for both parties in making sure you’re not working too many hours.

There are some industries exempt from the average working week limit; many employees will also have the option to opt-out, but the default position offers strong protection for the majority of the UK workforce which is why calculating working hours correctly is important.