Question 1

How do I work out hours worked including a break?

Accepted Answer

Take the finish time minus the start time, then subtract the unpaid break in minutes. A 09:00 to 17:30 day with a 30-minute lunch is 8 hours 30 minutes gross and 8 hours paid. This calculator does both steps and also shows the result as a decimal, which is what most payroll systems expect.

Question 2

Why does payroll use decimal hours instead of hours and minutes?

Accepted Answer

Because you cannot multiply 8 hours 30 minutes by an hourly rate directly. Converted to 8.5 decimal hours, the arithmetic is trivial. The conversion is minutes divided by 60, so 15 minutes is 0.25, 20 minutes is 0.33 and 45 minutes is 0.75.

Question 3

How does it handle shifts that run past midnight?

Accepted Answer

If the finish time is earlier than the start time, the calculator assumes the shift crosses midnight and adds a day. A 22:00 to 06:00 night shift is therefore counted as 8 hours rather than a negative number. Tick the multi-day option if the gap is longer than 24 hours.

Question 4

Should I round timesheet entries?

Accepted Answer

Rounding to the nearest 5, 6 or 15 minutes is common and generally acceptable as long as it is applied consistently and rounds both up and down — never only in the employer's favour. UK guidance is that workers must be paid at least the minimum wage for all time actually worked, so systematic rounding down risks underpayment.

Question 5

How many working hours are in a month?

Accepted Answer

There is no fixed answer, which is why salaried pay is usually averaged. A 37.5-hour week works out at about 162.5 hours a month on average, but individual months range from roughly 150 to 184 hours depending on how the weekdays and bank holidays fall.

Question 6

What counts as working time for breaks?

Accepted Answer

Under the UK Working Time Regulations, workers over 18 are entitled to an uninterrupted 20-minute rest break when working more than six hours a day. Whether that break is paid is a matter for the contract — many employers make lunch unpaid, which is why the break field here is deducted by default.

Question 7

How do I add several durations together?

Accepted Answer

Convert each one to minutes, add them up, then divide by 60 for the hours and take the remainder as the minutes. Adding hours and minutes directly is where mistakes creep in, because minutes carry at 60 rather than 100 — a spreadsheet formatted as a plain number will get this wrong.

Question 8

Does this calculator handle daylight saving changes?

Accepted Answer

It measures clock time, so a shift spanning the spring change appears an hour longer on paper than it was in real time, and an hour shorter in autumn. Most UK employers pay the rostered shift length rather than the clock difference, but it is worth checking your own policy for overnight shifts in late March and late October.

Time Duration Calculator

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How it works

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