Pro Rata Holiday Calculator for Leavers
Work out exactly how many holiday days you’ve earned up to your leaving date.
The Holiday Pay Mistake That Costs Leavers Every Year
Most people leaving a job assume HR will handle the holiday calculation correctly. And sometimes they do. But plenty of leavers walk away having either been underpaid holiday or — less commonly — having taken more than they earned, which can actually get deducted from that final pay packet.
The uncomfortable truth is that most payroll teams are busy, and errors in pro rata holiday calculations for leavers are more common than employers like to admit. You should always know your own number before your last day.
That’s exactly what this calculator is for. Enter your full-year entitlement, your holiday year start date, your leaving date, and how many days you’ve already taken — and it works out what you’re owed to the day.
How This Calculator Works Out Your Pro Rata Holiday
The logic behind a leaver holiday calculation is actually simple once you break it down. You’ve worked part of the holiday year, so you’re entitled to a proportional slice of your annual allowance — no more, no less.
Steps to Get Your Result
- Enter your full-year holiday entitlement in days. This is the total you’d receive if you worked the complete year — include bank holidays if your employer counts them in your allowance.
- Enter the start date of your current holiday year. This is often 1 January or 1 April, but check your contract — it varies by employer.
- Enter your actual leaving date (your last day of employment, not your notice start date).
- Enter how many holiday days you’ve already taken during this holiday year. If none, leave it as zero.
- Hit Calculate — the tool returns your pro rata entitlement and how many days remain owed to you.
The Formula Behind the Calculation
The calculation uses a straightforward proportional method based on UK statutory holiday entitlement rules, which require that leavers receive a fair portion of their annual leave based on time served.
The formula is:
Pro Rata Entitlement = (Days Worked ÷ Total Days in Holiday Year) × Full Annual Entitlement
Then: Holiday Owed = Pro Rata Entitlement − Days Already Taken
What Each Part of the Formula Means
Days Worked is counted from the first day of your holiday year up to and including your leaving date. The total days in the holiday year accounts for leap years automatically. Your full annual entitlement is whatever your contract states — for most UK workers this is 28 days including bank holidays, though many employers offer more.
A Worked Example With Real Numbers
Say your holiday year runs from 1 January to 31 December (365 days). You leave on 31 March, which is 90 days into the year. Your full entitlement is 28 days. You’ve already taken 5 days.
Pro rata entitlement = (90 ÷ 365) × 28 = 6.90 days earned. Minus 5 days taken = 1.90 days owed to you. Your employer should either let you take those days before you leave or pay them out in your final salary.
When This Calculation Really Matters Most
Not every leaver situation is the same. There are a few scenarios where getting this number right makes a genuine financial difference.
Leaving Mid-Year With a Generous Entitlement
Take someone with 33 days annual leave who leaves in October. They’ve worked roughly 75% of the year, so they’ve earned around 24.75 days. If they’ve only taken 15, that’s nearly 10 days owed — worth real money if paid out at daily rate. At a salary of £30,000, each day is worth roughly £115. Ten days adds up to over £1,100 in your final pay.
What Changes When Your Notice Period Is Involved
Your leaving date for this calculation is your last day of employment, not the day you handed in your notice. If you’re on gardening leave during your notice period, that time still typically counts — but this varies. Check your contract carefully and get clarity from HR in writing before your final day.
Three Things That Throw Off the Calculation
Using the Wrong Holiday Year Start Date
This is the most common mistake people make. They assume the holiday year starts on 1 January, but many companies run their year from April, or from the employee’s own start date anniversary. Using the wrong start date shifts every figure that follows. Your contract will state the correct date — look under the holiday or leave section.
Forgetting Half Days and Part Days
If you’ve taken any half-day leave, count it as 0.5. The calculation handles decimal days correctly, so be precise. Rounding half days up to full days before entering the number will skew the result.
Mixing Up Calendar Days and Working Days
This calculator works in calendar days for the year-fraction calculation, which gives the most accurate pro rata split. Your entitlement should still be entered in working days (or days as stated in your contract). Most UK employment law resources, including ACAS guidance on holiday entitlement, express entitlement in days rather than hours, so enter it exactly as your contract states.
Questions People Actually Ask When Leaving a Job
Can my employer refuse to pay out unused holiday when I leave?
In most cases, no. Under the Working Time Regulations, any accrued but untaken statutory holiday must be paid out on termination. Your employer can require you to take it during your notice period instead — but they can’t simply withhold it. There are limited exceptions for certain contract types, so check your specific terms if you’re unsure.
What if I’ve taken more holiday than I’ve earned by my leaving date?
This is called over-taken leave. Your employer may be legally entitled to deduct the value of those extra days from your final pay — but only if your contract explicitly allows it. If there’s no such clause, the situation becomes more complex and you’d want to take advice. The calculator flags this scenario so you’re not caught off guard.
Does my entitlement include bank holidays?
It depends on how your employer structures your leave. Some contracts say “28 days including bank holidays” — in that case, enter 28. Others say “20 days plus bank holidays” — in that case you may want to enter 28 (or however many bank holidays fall in your year) as the total. Enter the total number of days your contract says you receive for the year.
My holiday year starts on my work anniversary — how do I handle that?
Enter your work anniversary date as the holiday year start date. The calculator will count the days from that point to your leaving date and work out your entitlement based on the correct year-fraction. If you don’t know the exact date, check your original offer letter or contract.
I’m on a zero-hours or irregular hours contract — does this apply to me?
The formula is the same, but the entitlement calculation for zero-hours workers is often done differently — commonly using a 12.07% of hours worked method rather than a fixed annual days entitlement. This calculator is best suited to workers with a fixed annual days entitlement. If you’re on variable hours, your entitlement may need to be calculated separately before entering it here.
What counts as my leaving date — when I hand in notice, or my last day?
Your leaving date is your last official day of employment — the day your contract ends. That’s the date you should enter, not when you submitted your resignation. If you’re serving a notice period, your leaving date is the end of that notice period.
Can I use this calculator if I’m in the middle of a redundancy process?
Yes. If you’ve been given a confirmed last day of employment, enter that date. The pro rata holiday entitlement calculation works the same way regardless of the reason for leaving. Holiday owed forms part of your final pay regardless of whether you’re resigning, being made redundant, or ending a fixed-term contract.
What Do I Actually Do With This Number Once I Have It?
Once you’ve run the calculation, compare it against what your employer’s final pay statement shows. If there’s a discrepancy, raise it with HR or payroll in writing before your last day — it’s far easier to resolve while you’re still employed. Most errors are genuine mistakes and get corrected quickly when flagged. If the number shows you’ve over-taken holiday, it’s worth reviewing your contract to understand whether a deduction is permitted before your final pay is processed.