Seven days of hours, one weekly total, and where overtime kicks in.
A weekly total sounds simple — just add up seven days — but it's also where overtime starts to matter, so it's worth doing carefully rather than rounding as you go.
Monday through Friday, 9:00 AM to 5:00 PM with a 30-minute lunch each day (7h 30m per day), and Saturday 9:00 AM to 1:00 PM with no break (4h).
Since the threshold is 40 hours, 1 hour 30 minutes of that week is overtime. Check the same schedule in the Weekly Time Calculator for the day-by-day total, or the Overtime Calculator to see the regular/overtime pay split.
The most useful reason to calculate a weekly total carefully — rather than eyeballing it — is to catch the moment a week crosses whatever threshold your contract uses for overtime. Unlike some countries, the UK has no statutory overtime threshold or rate; whether extra hours are paid, and from what point, depends entirely on your employment contract. Many contracts do use 40 hours as the point where an enhanced rate kicks in, simply because it's a common full-time week, but that's a contractual choice, not a legal requirement.
Continuing the example above, say a contract pays £18 an hour with a 1.5x rate after 40 hours a week. That 41h 30m week breaks down as 40 regular hours and 1.5 hours (1 hour 30 minutes) of overtime.
Check this against the Overtime Calculator by entering 41.5 total hours, a 40-hour threshold, £18 rate, and 1.5 multiplier — then try changing the threshold and multiplier to match your own contract's terms, since they may well be different.
A pay period and a working week aren't always the same thing. Many employers pay every two weeks or every month, but if your contract calculates any overtime premium on a weekly basis, it's worth totalling each week separately rather than only looking at the combined pay-period figure. That way a strong week and a quiet week don't accidentally cancel each other out when checking whether an overtime rate should have applied.
The same weekly-total process works exactly the same way for a part-time or variable schedule — there's no separate formula. If someone works 4 hours on Monday, skips Tuesday and Wednesday, works 6 hours Thursday, and 5 hours Friday, the weekly total is still just the sum of every day worked (4 + 0 + 0 + 6 + 5 = 15 hours), with days off simply contributing zero rather than being skipped in the addition. Keeping every day of the week in the total, even the zero days, makes it much easier to spot a missing entry later.
Beyond overtime, a clear weekly total is simply the record most disputes get resolved against — if a payslip looks short, the first thing to check is whether the weekly total on the payslip matches an independent total worked out from the actual clock-in and clock-out times. Keeping your own running total, even a simple one, gives you something concrete to compare against rather than relying on memory of roughly how many hours a week felt like. It's also worth remembering that, whatever your contract says about overtime, your average pay for all hours worked must never fall below the National Minimum Wage or National Living Wage.
Estimates only. Not legal, tax, or payroll advice.