How to calculate timesheet hours and pay correctly

Timesheets look simple until you try to add 7 hours 45 minutes to 8 hours 20 minutes and multiply by an hourly rate. Hours and minutes use a base of 60, money uses a base of 100, and breaks, overtime and rounding rules sit on top. This guide shows how to work out a day's hours from start and finish times, how to turn minutes into decimals so you can multiply by a pay rate, how to handle unpaid breaks and overtime, and how to check that a rate meets the National Minimum Wage rates in force from April 2026. All the figures are worked through so you can follow along with your own times.

By Valtrinity. Updated 18 October 2026.

Step 1: work out the hours for each day

Subtract the start time from the finish time, then subtract any unpaid break. Use the 24-hour clock if you can, because it removes the am and pm confusion. A shift from 08:45 to 17:15 lasts 8 hours 30 minutes. If you take a 45-minute unpaid break, the working time is 7 hours 45 minutes.

When the finish minutes are smaller than the start minutes, borrow an hour. A shift from 09:50 to 17:20 is 7 hours 30 minutes: from 09:50 to 17:00 is 7 hours 10 minutes, and 20 more minutes makes 7 hours 30 minutes.

For a shift that crosses midnight, split it at midnight. A night shift from 22:00 to 06:00 is 2 hours until midnight plus 6 hours after it, which is 8 hours. If there is a 30-minute unpaid break, the working time is 7 hours 30 minutes.

Step 2: turn minutes into a decimal

To multiply hours by a pay rate, you need decimal hours. Divide the minutes by 60 and add them to the whole hours. 45 minutes is 45 divided by 60, which is 0.75, so 7 hours 45 minutes is 7.75 hours. 30 minutes is 0.5, 15 minutes is 0.25, 20 minutes is 0.333 and 10 minutes is 0.167.

The most common mistake is to write 7 hours 30 minutes as 7.30. That is 7.3 hours, which is 7 hours 18 minutes. The correct decimal is 7.5. In the same way, 7.75 hours is not 7 hours 75 minutes. To go back the other way, take the decimal part and multiply by 60: 0.75 times 60 is 45 minutes.

A table of common values helps: 5 minutes is 0.08 hours, 10 is 0.17, 15 is 0.25, 20 is 0.33, 30 is 0.5, 40 is 0.67, 45 is 0.75 and 50 is 0.83.

Step 3: add up the week

Add the decimal hours for each day. Imagine a week with these working times: Monday 8.0, Tuesday 8.0, Wednesday 7.75, Thursday 8.75 and Friday 6.0. The total is 8 plus 8 plus 7.75 plus 8.75 plus 6, which is 38.5 hours.

You can also add in hours and minutes. Monday 8:00, Tuesday 8:00, Wednesday 7:45, Thursday 8:45 and Friday 6:00. Add the hours: 8 plus 8 plus 7 plus 8 plus 6 is 37. Add the minutes: 45 plus 45 is 90 minutes, which is 1 hour 30 minutes. The total is 38 hours 30 minutes, the same as 38.5.

Doing it both ways is a good check. If the two do not agree, a decimal or a carried hour has gone wrong.

Step 4: multiply by the hourly rate

Multiply the decimal hours by the rate. At £12.71 an hour, 38.5 hours earns 38.5 times 12.71, which is £489.34, rounded to the nearest penny (the exact figure is £489.335).

For someone contracted for 37.5 hours a week at £12.71 an hour, the basic weekly pay is 37.5 times 12.71, which is £476.63 (exactly £476.625). If they work 1 extra hour and the employer pays overtime at time and a half, the extra hour earns 12.71 times 1.5, which is £19.07, so the week comes to £495.69 before tax.

Round at the end, not in the middle. If you round each daily figure to the penny and then add them, the total can be a penny or two different from the weekly calculation, which can matter when payroll checks the result.

Breaks, overtime and rounding

Unpaid breaks are taken off the working day, and breaks that count as working time are not. Under the Working Time Regulations, workers aged 18 and over are entitled to an uninterrupted rest break of at least 20 minutes if they work more than six hours, but whether that break counts as working time depends on the contract.

Overtime is the time worked beyond normal hours. There is no general legal right to a higher overtime rate: it is a matter for the contract. Common arrangements are time and a half (1.5 times the normal rate) or double time (2 times). Whatever is agreed, the average pay over the pay period must still be above the minimum wage.

Some employers round clock-in times, for example to the nearest 15 minutes. If rounding always goes in the employer's favour, it can reduce pay below what is due, so check the policy. Where a system rounds, the rule should be fair and even across the year.

Checking against the minimum wage

From 1 April 2026 the National Living Wage for workers aged 21 and over is £12.71 an hour. The National Minimum Wage is £10.85 for those aged 18 to 20, £8.00 for under-18s and £8.00 for apprentices in the age bands where the apprentice rate applies. Rates change each April, so always check GOV.UK for the current rate.

To check your own pay, divide the pay for a period by the hours worked. If you earn £400 for 35 hours, the hourly rate is 400 divided by 35, which is £11.43. For someone aged 21 or over, that is below £12.71, so it would be worth checking whether anything is wrong, taking into account any rules on deductions and accommodation.

Time that counts as working time for minimum wage purposes can include some things people forget, such as travel between assignments and time on call at the workplace. Unpaid breaks do not count. If you think you are being underpaid, GOV.UK has a pay check tool and Acas can advise.

Practical tips for timesheets

Record start, finish and break times, not just a total. A total hides errors, but the times let you recalculate. Keep the same format throughout, either all 24-hour or all 12-hour with am and pm.

Check weekly totals against the limit on working time. The average weekly working time is 48 hours, normally measured over 17 weeks, though workers can choose to opt out. If your timesheet regularly shows more than that, it is worth a conversation.

Keep a copy of each timesheet. If the pay is wrong, you will want to show what you worked. Where the sheet feeds payroll, submit it on time and check the pay slip against your calculation.

Tools mentioned in this guide

Frequently asked questions