Working Hours Calculator
Calculate your annual, monthly, and weekly working hours. Check Working Time Directive compliance, overtime pay, and FTE ratios instantly.
Standard UK full-time: 7.5 or 8 hours (excluding lunch)
Full-time: 5 days. Part-time: enter your contracted days.
Subtract Holiday Entitlement
UK statutory minimum: 28 days (5.6 weeks)
Weekly Hours
37.5
Monthly Average
145
Gross Annual
1,950
Net Annual
1,740
210 hours deducted for 28 days holiday
Working Time Directive
37.5 hours/week is within the 48-hour weekly limit.
1,950 hrs/year
2,080 hrs/year
2,496 hrs/year
All workers, 2025
Tip: Common FTE values: 1.0 (full-time), 0.8 (4 days), 0.6 (3 days), 0.5 (half-time)
UK Working Time Regulations
The Working Time Regulations 1998 (WTR) implement the EU Working Time Directive into UK law. They set out the maximum weekly working hours, minimum rest breaks, and night work limits that apply to almost all workers in the United Kingdom. These regulations were retained in UK law after Brexit and continue to apply in full.
The regulations apply to most workers, including agency workers, freelancers who are classed as workers, and part-time staff. Some sectors have modified rules, including the armed forces, emergency services (in certain circumstances), and workers in transport sectors who are covered by separate regulations.
Understanding these regulations is essential for both employers and employees. Employers must ensure compliance to avoid enforcement action from the Health and Safety Executive, while employees should know their rights to adequate rest, reasonable working hours, and protection from being penalised for asserting those rights.
Maximum Weekly Working Hours
The Working Time Regulations cap the average working week at 48 hours, calculated over a reference period of 17 weeks. This means occasional weeks over 48 hours are permissible, provided the average across the reference period stays within the limit. The reference period can be extended to 26 weeks by collective or workforce agreement in certain circumstances.
The 48-hour limit includes any overtime worked, whether paid or unpaid. It does not include travel time to and from work (unless the worker has no fixed workplace), paid or unpaid holiday, sick leave, or rest breaks.
The 48-Hour Opt-Out
Workers aged 18 or over can voluntarily agree to work more than 48 hours per week by signing a written opt-out agreement. Key rules:
- The opt-out must be voluntary — employers cannot force or pressure workers to sign
- Workers can cancel the opt-out at any time by giving written notice (minimum 7 days, or up to 3 months if specified in the agreement)
- Workers cannot be dismissed or subjected to any detriment for refusing to opt out
- Workers under 18 cannot opt out and are limited to 40 hours per week
- Employers must keep records of workers who have opted out
Note: The UK is one of the few countries that allows individual opt-outs from the 48-hour limit. Many EU countries do not permit individual opt-outs. The opt-out was negotiated as part of the original EU Working Time Directive.
Rest Breaks and Rest Periods
The Working Time Regulations give workers the right to adequate rest breaks during the working day, between working days, and each week. These minimums cannot be contracted out of by the employer, and workers cannot be disadvantaged for taking their statutory rest entitlements.
Daily Rest Break
20 minutes
Uninterrupted break if working more than 6 hours. Must be away from the workstation. Under-18s: 30 minutes after 4.5 hours.
Between Shifts
11 hours
11 consecutive hours of rest between finishing one working day and starting the next. Under-18s: 12 hours.
Weekly Rest
24 hours
One uninterrupted 24-hour period each week, or 48 hours per fortnight. Under-18s: 48 hours per week.
Important: Rest breaks are not always paid — this depends on your employment contract. The law only requires that the break is given, not that it is paid. Many employers include a paid break as a contractual benefit.
Night Worker Limits
Night workers are subject to additional protections under the Working Time Regulations. A night worker is someone who regularly works at least 3 hours of their daily working time during the night period, which runs from 11pm to 6am by default (this can be varied by collective agreement, but must always include midnight to 5am).
Night workers must not work more than an average of 8 hours in each 24-hour period, averaged over a 17-week reference period. Where night work involves special hazards or heavy physical or mental strain, the limit is an absolute 8 hours in any 24-hour period with no averaging allowed.
Free health assessments
Employers must offer night workers a free health assessment before they start night work and at regular intervals afterwards. If a health professional advises that a worker should transfer to day work, the employer should do so if reasonably practicable.
Record keeping
Employers must keep records of night workers' hours, sufficient to prove compliance with the 8-hour average limit. These records must be kept for at least 2 years and be available for inspection by the Health and Safety Executive.
Young workers
Workers under 18 are generally prohibited from working between 10pm and 6am (or 11pm and 7am). There are limited exceptions for certain industries, but young workers should not normally be performing night work.
Record-Keeping Requirements
UK employers have a legal obligation to maintain adequate records to demonstrate compliance with the Working Time Regulations 1998. While the regulations do not prescribe a specific format for record-keeping, the records must be sufficient to show that the limits on working hours, night work, and rest entitlements are being observed.
The Health and Safety Executive (HSE) is responsible for enforcing the working time limits, while employment tribunals handle complaints about rest breaks and annual leave. Employers who fail to maintain adequate records can face enforcement notices and, in serious cases, prosecution.
What Employers Must Record
- Hours worked by each employee (sufficient to prove the 48-hour average is not exceeded)
- Signed opt-out agreements for any workers who have agreed to exceed 48 hours
- Night worker hours (to demonstrate compliance with the 8-hour average)
- Health assessment offers and outcomes for night workers
- Annual leave entitlement, requests, and days taken
- Records must be retained for at least 2 years
Modern HR software like Grove automates much of this record-keeping. Working hours are tracked automatically through timesheets and leave records, opt-out agreements can be stored in employee profiles, and reports can be generated on demand to demonstrate compliance during an audit or inspection. Read more about overtime tracking and how to manage it effectively.
Frequently Asked Questions
How many working hours are in a year in the UK?
For a standard full-time employee working 37.5 hours per week, there are approximately 1,950 gross working hours per year (37.5 x 52 weeks). After deducting the 28-day statutory holiday entitlement (210 hours at 7.5 hours per day), the net working hours are approximately 1,740. If you work 40 hours per week, the gross figure is 2,080 and the net is around 1,856 after holidays. The exact figure depends on your contracted hours, holiday entitlement, and working pattern.
What is the maximum number of hours I can work per week in the UK?
Under the Working Time Regulations 1998, the maximum average working week is 48 hours, calculated over a 17-week reference period. Workers aged 18 or over can voluntarily opt out of this limit by signing a written agreement. The opt-out can be cancelled by giving written notice (minimum 7 days, or up to 3 months if specified in your agreement). Your employer cannot force you to opt out or treat you unfairly for refusing. Workers under 18 cannot work more than 40 hours per week under any circumstances.
What rest breaks am I entitled to at work?
UK workers are entitled to: a 20-minute uninterrupted rest break if working more than 6 hours in a day (the break should be taken during the shift, not at the start or end); 11 consecutive hours of rest between working days; and at least one uninterrupted 24-hour period without work each week (or 48 hours per fortnight). Young workers (under 18) get enhanced entitlements: 30 minutes after 4.5 hours, 12 hours between shifts, and 48 hours per week.
How do I calculate FTE for a part-time employee?
Divide the employee's actual weekly hours by the organisation's standard full-time hours. For example, if your full-time week is 37.5 hours and the employee works 22.5 hours, their FTE is 22.5 / 37.5 = 0.6. This means they are working at 60% of a full-time role. FTE is used for budgeting, headcount reporting, pro-rata holiday calculations, and benchmarking workforce capacity. A team of three 0.5 FTE employees is equivalent to 1.5 full-time employees.
Is there a legal right to overtime pay in the UK?
No, there is no statutory right to overtime pay in the UK. Whether you receive overtime pay, and at what rate, depends entirely on your employment contract. Common contractual overtime rates include time-and-a-half (1.5x) and double time (2x), but some employers pay overtime at the standard hourly rate. The only legal requirement is that your average hourly pay across all hours worked (including overtime) must not fall below the National Minimum Wage (£12.21 per hour for workers aged 21+ from April 2025).
What are the rules for night workers?
Night workers (those who regularly work at least 3 hours between 11pm and 6am) must not average more than 8 hours per 24-hour period over a 17-week reference period. Where the work involves special hazards or heavy strain, the 8-hour limit is absolute (no averaging). Employers must offer free health assessments to night workers before they start and regularly thereafter. Night workers should be transferred to day work if a health professional recommends it and it is reasonably practicable.
Do employers have to keep records of working hours?
Yes, employers must keep records sufficient to demonstrate compliance with the Working Time Regulations. This includes evidence that workers are not exceeding the 48-hour average (or have signed opt-out agreements), that night workers are within the 8-hour average, and that rest breaks are being provided. Records must be retained for at least 2 years. The Health and Safety Executive can inspect these records, and failure to maintain them can result in enforcement action.
Can my employer force me to work more than 48 hours a week?
No. The 48-hour opt-out must be voluntary. Your employer cannot require you to sign an opt-out agreement as a condition of employment, and cannot dismiss you or subject you to any detriment for refusing to sign one. If you have previously signed an opt-out, you can cancel it by giving written notice. If you believe your employer is forcing you to work excessive hours, you can contact ACAS or make a complaint to the Health and Safety Executive.
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