How much annual leave you get in the UK
Most people in the UK are entitled to 5.6 weeks of paid holiday a year. That's the statutory minimum set by the Working Time Regulations, and for someone on a normal five-day week it works out at 28 days. An employer can be more generous, and plenty offer 25 days plus bank holidays. What they can't do is go below 28 for a full-timer.
Are bank holidays on top, or included?
Legally, there's no automatic right to take bank holidays off at all, and no right to extra pay for working them. What the law guarantees is the 5.6 weeks, and an employer is allowed to count the bank holidays inside it. So "28 days including bank holidays" means 20 days you choose plus the 8 fixed ones. "20 days plus bank holidays" is the same 28 dressed differently. "25 plus bank holidays" is genuinely more. It's worth checking which your contract actually says, because they sound alike but aren't.
Part-time work
You get the same 5.6 weeks, scaled to your week. Work three days and you're entitled to 5.6 × 3 = 16.8 days. The awkward fraction is normal; some employers round up, and holiday for part-timers is often easier to think about in hours than in days.
The 28-day cap
The 5.6 weeks is capped at 28 days. So a six-day week still gets 28 as its statutory floor, not 33.6, though again a contract can offer more.
Carrying leave over
As a rule, statutory holiday is use-it-or-lose-it: you're meant to take it within the leave year. A limited amount can be carried into the next year if your employer agrees, and there are cases, such as long-term sickness or maternity leave, where unused days have to be carried. But don't assume leave rolls over by default.
For an exact figure in an unusual case, such as irregular hours or a job you started partway through the year, the gov.uk holiday entitlement calculator is the definitive source.
Once you know your number, put your allowance into the planner, tell it whether bank holidays are on top or included, and it shows how far the year's leave will stretch.