Holiday Hours Calculator: Set the Right Holiday Allowance
No matter the shape or size of your business, calculating holiday time always feels a bit like a puzzle.
UK employment law sets a clear minimum for annual leave, but translating that into the right number of hours for each individual member of your staff isn’t always straightforward (especially if you have a mix of full-time, part-time, and casual workers).
The good news is that, once you have a clear guide and calculator, calculating holiday hours is a lot easier than you might think.
What does the law say about holiday entitlement in the UK?
Under UK employment law, workers are legally entitled to at least 5.6 weeks’ paid holiday each year, which includes 20 days of statutory holiday and 8 bank holidays. This rule is applied to full-time, part-time, and casual (zero-hours) workers.
For full-time employees who work five days per week, this works out to 28 days of paid holiday each year. This allowance can include bank holidays, and employers are not required to give bank holidays as extra days on top of the legal minimum.
For part-time employees, holiday entitlement still equates to 5.6 weeks each year, but the number of holiday days given is based on the average number of days or hours worked each week.
For casual, irregular, or zero-hours workers, holiday entitlement also equates to 5.6 weeks each year. In this case, holiday time accrues based on the number of hours worked. Calculating the 5.6 weeks entitlement for these workers can be calculated as 12.07% of the actual hours worked. And since the update in January 2024 (if it’s easier), you can now roll up holiday pay by adding 12.07% each time a zero-hours worker is paid. As a best practice, always make a clear distinction between wages and rolled up holiday pay on each payslip.
How can a holiday hours calculator help?
A holiday hours calculator takes away the complexity and guesswork involved with calculating holiday entitlement. Instead of relying on spreadsheets or manual calculations, a holiday hours calculator does the maths for you. This is especially helpful if your team has a mix of full-time, part-time, and variable hours.
When paired with a clear holiday entitlement framework, holiday calculators give both you and your staff confidence in knowing that annual leave is being handled correctly.
How to calculate holiday allowance manually
Using a holiday hours calculator is the most accurate way to calculate annual leave, and it saves you a ton of time. But it’s still a good idea to have a basic understanding of how the numbers are calculated, just in case you ever need to check a figure on the spot or explain your calculations to an employee.
| Category | Calculation | Example |
|---|---|---|
| Full-time staff on fixed days/hours | Start with the legal minimum (5.6 weeks’ leave per year). | 5 days × 5.6 = 28 holiday days per year |
| Part-time staff on fixed days/hours | Start with the legal minimum (5.6 weeks’ leave per year) and the number of hours worked in a normal week. | 20 hours × 5.6 = 112 holiday hours per year |
| Casual, seasonal, or zero-hours staff | Start with the actual number of hours worked in a pay period and apply the 12.07% rule . | 30 hours × 12.07% = 3.621 → rounded to 4 holiday hours |
| Mid-year starters or leavers (full-time) | Start with the proportion of the year worked. | 28 ÷ 2 = 14 holiday days for half the year |
What about bank holidays?
The 8 bank holiday days are included within the 28 day days of annual entitlement. However, your staff don’t necessarily have to take the actual bank holidays off. For example, they could choose to work on Easter Monday, but take another day off instead.
For part-time or irregular staff, you can consider pro-rating bank holidays. For example, if someone works three out of five working days per week, they would receive 3/5 of the bank holiday entitlement.
However you choose to manage bank holidays, it’s important to make your approach clear in your employment contract to avoid confusion and disappointment.
Why it’s important to get holiday allowance right
Having a clear holiday allowance policy in place is a legal requirement under UK law. Beyond that, it’s also vital for employee wellbeing and keeping your business running smoothly.
When holiday allowance is calculated correctly, your organisation benefits in the following ways.
Compliance with UK employment law.
The legal minimum leave (for most workers) is 5.6 weeks a year. However, the way this is calculated can vary depending on contracts and working patterns. Calculation errors here can lead to disputes, back payments, and even tribunal claims, so it’s important to get your calculations right.
Your team feels valued.
When your staff understand exactly how their holiday entitlement is calculated and they can see it’s applied consistently, they feel safe to take their leave. Over time, this builds trust between your employees and your business.
Planning and scheduling is easier.
Knowing exactly how much leave each employee has makes it easier to approve requests, plan cover, and avoid last-minute disruptions to workflows. Clear, accurate calculations from the start prevent misunderstandings and save time spent on corrections later.
Best practices for managing holiday leave in small teams
Absences are especially felt in small, growing teams. Here are a few practical tips for managing holiday expectations and keeping work running smoothly:
Use a simple HR system to automate approvals and keep your calendar up to date.
Set clear notice periods and limits, such as “time off must be booked at least 2 weeks in advance.”
Spread leave fairly, especially in busy or seasonal periods.
Establish carry-over guidelines. By law, workers can only carry over unused leave in very limited cases. Having clear carry-over guidelines helps avoid confusion at year-end and sets fair expectations for everyone.
Consider working with an HR Partner to help create and maintain holiday policies that are legally compliant, easy to implement, and consistent across your business.
With clear policies, fair scheduling, and open communication, you can make sure time off works for your business and your people. A little planning up front means fewer last-minute surprises and a team that returns from leave feeling refreshed and ready to contribute.
Final thoughts
Holiday entitlement can seem so straightforward on paper. But it can quickly become complicated when different working patterns and contract types are involved.
Using a holiday hours calculator together with a clear, well-communicated absence policy gives your business the structure it needs for:
Handling leave fairly and
Staying compliant with UK law.
For teams, this means fewer disruptions, smoother planning, and an overall healthier workplace culture.
Struggling to figure out holiday allowance for your part-time staff?
Leave the maths to us by downloading our free Part-Time Annual Leave Calculator.