How Many Days Holiday Am I Entitled To Working a 4-Day Week?

The short answer

If you work 4 days a week, your statutory minimum holiday entitlement is 22.4 days per year (4/5 × 28). This is the legal minimum under the Working Time Regulations 1998. Your employer cannot give you less than this.

But there is a catch: whether those 22.4 days include or are in addition to bank holidays makes a big practical difference. Keep reading.

The formula: how we got to 22.4

The statutory minimum for a full-time worker (5 days a week) is 28 days (5.6 weeks × 5 days). For part-time workers, entitlement is pro-rata — proportional to the days you work.

Formula: (Your working days ÷ 5) × 28

4-day week: (4 ÷ 5) × 28 = 22.4 days

Your employer must give you at least 22.4 days. They cannot round down to 22 — that would be below the statutory minimum.

What about bank holidays?

If your contract says "28 days including bank holidays" and you work 4 days a week: your total entitlement is 22.4 days. If a bank holiday falls on one of your normal working days, it counts as part of your 22.4 days. If it falls on your non-working day, you do not lose a day.

If your contract says "20 days plus bank holidays", you get (4/5 × 20) = 16 days of flexible holiday, plus bank holidays on your working days.

Worked example

Sarah works Tuesday–Friday (4 days). Her pro-rata entitlement is 22.4 days. In 2026, 7 of the 8 bank holidays fall on weekdays. Only those landing on Tue–Fri count against her allowance. Use our calculator to check your exact entitlement.

What if my employer gets it wrong?

If your employer gives you fewer than 22.4 days (for a 4-day week) or counts bank holidays against you when they fall on your non-working days, raise it informally first, then follow the formal grievance process. ACAS (0300 123 1100) can provide free advice.

What 22.4 days looks like across a year

Twenty-two point four days is not a neat number of weeks, which is where people get confused. If you work four days a week and take holiday in whole days, the practical entitlement is usually expressed as 22 days plus a bit — and how the employer handles the half-day matters.

Three legitimate approaches:

• 22.5 days — rounded up. Common and lawful, because rounding up never takes you below the statutory minimum.
• 22 days plus one half-day — the precise figure expressed honestly.
• 22 days — not lawful on its own. Rounding down takes you below 5.6 weeks.

If your employer's system only books whole days, ask how they account for the 0.4. Some carry it as a half-day; others let it accrue and apply it to a shorter day. What they cannot do is quietly drop it.

Mid-year starters and leavers on a four-day week

Entitlement accrues from your first day. If you join part-way through the leave year, your 22.4 days is pro-rated again for the portion of the year you are employed.

Example: the leave year runs January to December. You start on 1 September on a four-day week, so you are employed for 122 of 365 days. Your entitlement for that year is 22.4 × (122 ÷ 365) = 7.5 days.

If you leave mid-year, the same calculation applies to the part of the year you worked, and the employer may recover holiday you were paid for but had not yet accrued — but only where the contract clearly allows it. Deductions from a final payslip that take you below the National Minimum Wage are not permitted.

Contract traps to check

• A clause giving "20 days plus bank holidays" produces a different total from "28 days including bank holidays" — work out which yours says before assuming you are short-changed.
• "Pro-rata" must still land at or above 22.4 days for a four-day week. A contract cannot contract out of the statutory minimum.
• Some contracts define a day's pay using a fixed divisor (for example salary ÷ 260). That can underpay part-time staff if the divisor does not reflect their actual working pattern.
• Bank holidays that fall on your non-working days must not be deducted from your allowance.

If your employer rounds down

Start with a written query, quoting the regulation and your calculation. Most employers correct it quickly once it is framed as a specific number rather than a general complaint. If they refuse, ACAS advice is free on 0300 123 1100, and unpaid statutory holiday is recoverable as an unlawful deduction from wages at an employment tribunal.