How to calculate holiday entitlement | annual leave guide

Learning how to work out holiday entitlement can be a tricky process for growing businesses. However, there are easy ways to calculate holiday entitlement for workers, whether they're full-time, part-time, or working irregular hours. Learn how to calculate annual leave and get great holiday management tips in this guide from myhrtoolkit.

Calculating full time holiday entitlement

Every worker in the UK, whether full-time, part-time, irregular-hours, or part-year, has a legal right to a minimum of 5.6 weeks' paid annual leave each year (equivalent to 28 days for a five-day week).

Significant reforms introduced from 1 January 2024 and applied to leave years starting from 1 April 2024 have reshaped how holiday entitlement and pay are calculated, particularly for workers with variable patterns. This comprehensive guide explains these changes and demonstrates how modern employers can exceed basic compliance to foster fairness, wellbeing, and flexibility in their workplace culture. 

Related article: Holiday leave notice: how to manage holiday requests

Statutory holiday entitlement: full-time and fixed part-time workers 

Standard entitlement 

All workers in the UK are entitled to 5.6 weeks of paid annual leave per year. This includes bank holidays, though employers are not legally required to offer bank holidays as separate paid leave. 

Full-time workers (5 days/week): 
5 days × 5.6 weeks = 28 days paid leave annually 

Part-time workers with regular patterns:  
Holiday entitlement is calculated proportionally based on working days: 

• 1 day/week = 5.6 days annually
• 2 days/week = 11.2 days annually
• 3 days/week = 16.8 days annually
• 4 days/week = 22.4 days annually

Handling Fractional Days 

Holiday entitlement calculations may result in fractional days (e.g., 16.8 days). These cannot be rounded down, but employers may choose to: 

• Round up to the nearest full day
• Allow taking a full day off with payment for the fractional entitlement
• Offer flexible arrangements (adjusting shift times, leaving early/arriving late)

Irregular-hours and part-year workers: new accrual system 

Updated definitions (effective from April 2024) 

• Irregular-hours worker: Someone whose hours are wholly or mostly variable per pay period (e.g., zero-hours contract employees, casual workers)
• Part-year worker: Someone who only works or gets paid for part of the year, with gaps of at least one week (e.g., seasonal workers, term-time only employees)

Accrual calculation method Holiday accrual

For leave years starting on or after 1 April 2024, these workers accrue holiday as follows: 

• Holiday accrues at 12.07% of actual hours worked in each pay period
• Accrual takes place on the last day of the pay period

Accrual calculation method Holiday accrual

• Less than 30 minutes (0.5 hour): Round down to the nearest hour
• 30 minutes (0.5 hour) or more: Round up to the nearest hour

Example: If a monthly-paid worker works 100 hours in a month, they accrue 12.07 hours, which rounds to 12 hours of annual leave. 

Holiday pay for irregular workers 

For the statutory 4 weeks (20 days): 

• Must be paid at the worker’s “normal remuneration”
• Includes regular commission, seniority payments, and overtime averaged over the prior 52 weeks

For the additional 1.6 weeks (8 days): 

• Can be paid at basic rate
• Employers may choose to implement “rolled‑up holiday pay” (paid with regular wages) provided it is itemised separately on payslips

Holiday requests and notice requirements

Employee notice requirements

Employees must provide notice that's at least twice the length of the holiday requested: 

• 1 day off = minimum 2 days’ notice
• 1 week off = minimum 2 weeks’ notice

Employer refusal rights 

Employers can refuse holiday requests but must give notice equal to the length of the requested leave: 

• To refuse 1 day = minimum 1 day’s notice
• To refuse 1 week = minimum 1 week’s notice

Managing busy periods

Employers may specify restricted dates in employment contracts, provided this doesn't prevent staff from taking their full statutory leave entitlement during the leave year.

First year employment and accrual

Accrual during first year 

For all workers in their first year of employment: 

• Leave accrues at 1/12 of annual entitlement per month worked
• Workers cannot take “negative” holiday days unless specifically agreed by the employer
• Pro-rata calculations apply based on start date and leave year

Carry-over rights 

• Employers must allow unused statutory leave to be carried over to the next leave year
• This is particularly important when leave wasn’t taken due to sickness or family-related leave
• Enhanced contractual leave (beyond statutory minimum) may have different carry-over rules

Modern best practices: beyond legal compliance 

Today's leading employers are embracing evolving workplace values that prioritise transparency, flexibility, and employee wellbeing: 

Communication and transparency 

• Simplify explanations: Clearly communicate holiday accrual methods and pay calculations to all staff
• Provide regular updates: Use payslips and HR systems to show accrued leave balances
• Create accessible policies: Ensure holiday policies are easy to understand and readily available

Promoting work-life balance 

• Encourage leave usage: Actively promote the importance of taking full annual leave entitlement
• Prevent burnout: Monitor employees who consistently under-use their leave
• Offer flexibility: Consider allowing holiday requests before full accrual where operationally feasible

Inclusive and fair practices 

• Avoid discrimination: Ensure overtime and irregular hours don’t unfairly impact holiday entitlements
• Cultural sensitivity: Respect religious and cultural holidays with clear, inclusive leave management policies
• Equal treatment: Apply holiday policies consistently across all worker categories

Technology and automation 

• HR software solutions: Implement systems to automatically track accruals, calculate pay, and manage carry-over
• Self-service portals: Enable employees to view balances and submit requests online
• Compliance monitoring: Use technology to ensure ongoing adherence to changing regulations

Summary: holiday entitlement quick reference

Key compliance dates 

• 1 January 2024: New regulations took effect
• 1 April 2024: Implementation deadline for leave years starting from this date
• Ongoing: All new leave years must follow updated calculation methods

How to calculate part-time holiday entitlement

Things get a bit more complicated when it comes to calculating part-time holiday entitlement. How much holiday a part-time worker gets depends on how many days they are working per week. This is called pro-rata entitlement, as the part time employee’s holiday is proportional to a full time employee’s holiday entitlement.

To work out how much annual holiday a part-time worker is entitled to, multiply the number of days they work a week by 5.6 to get their result. Here are some examples:

• 4 days per week = 22.4 holiday days (4 x 5.6)
• 3.5 days per week = 19.6 holiday days (3.5 x 5.6)
• 3 days per week = 16.8 holiday days (3 x 5.6)
• 2.5 days per week = 14 holiday days (2.5 x 5.6)
• 2 days per week = 11.2 holiday days (2 x 5.6)
• 1.5 days per week = 8.4 holiday days (1.5 x 5.6)
• 1 day per week = 5.6 holiday days (1 x 5.6)

Find out more in our guide on calculating holiday entitlement for part time workers.

Bank holidays for part-time workers

Bank holidays can be another complication when it comes to holiday entitlement for part time workers. For instance, someone who works Wednesdays and Thursdays is not likely to be affected by bank holidays. This can be problematic, as these employees could be receiving fewer holidays than their colleagues if your organisation provides paid bank holidays on top of statutory entitlement.

Bank holiday allowance for part-time workers

To address this, some organisations give part-time workers a pro-rata bank holiday allowance. To work out a part-time worker’s bank holiday allowance in hours, you need to divide the worker’s weekly hours by a full-time worker’s weekly hours. Then multiply this by the full-time worker’s full bank holiday entitlement.

For example, say a part-time worker works 14 hours a week (2 days). Your full-time workers work 35 hours (5 days) and have 56 hours of bank holiday per year (8 days). The calculation would be:

14 ÷ 35 x 56 = 22.4 hours

22.4 hours equates to 3 days and a few hours; this should round up to the nearest full or half day if you do not provide hours off. You legally cannot round down.

Read more: Bank holiday entitlement for part time workers

Calculating holiday entitlement in hours

Some people work hours instead of full days, so the calculations above don't work for every type of worker. See our article on calculating holiday entitlement in hours to find out how to calculate holiday entitlement for employees with regular and irregular hours.

Conclusion

Calculating holiday entitlement and pay in line with UK law requires navigating clear statutory rules, including updated definitions, accrual methods, normal pay calculations, and optional rolled-up pay for certain worker categories. However, organisations that move beyond minimum compliance to embrace fairness, transparency, and employee wellbeing (particularly for those on variable or unpredictable hour) will build stronger trust and create a more supportive, modern workplace culture.

The 2024 reforms represent a significant shift towards fairer treatment of flexible workers. By understanding these changes and implementing thoughtful policies that exceed basic requirements, employers can ensure compliance while demonstrating genuine commitment to their workforce's wellbeing and work-life balance.

Disclaimer: This guide provides general information about UK employment law as of 2025. It should not be considered as legal advice. For specific situations, consult with qualified employment law professionals.

Related article: Managing sickness and annual leave when they overlap

Tired of holiday tracking and admin?

Tracking holidays and calculating holiday entitlement can be a time-consuming process. This can be particularly true if you've got a growing business with a number of new starters and occasional leavers. Thankfully, HR software can help you automate holiday admin with automatic entitlement calculations!

To find out more, head over to our annual leave software feature page to see how HR software can help you break free from the admin involved in approving holidays, tracking annual leave, and calculating entitlements.