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.