Work Hours Calculator
Calculate daily and weekly work hours with break deductions. Track overtime, see monthly estimates in both decimal and HH:MM formats
Daily Work Hours
Weekly Total
37.5
hrs (Mon-Fri)
Monthly Est.
162.38
hrs/month
How to Use the Work Hours Calculator
In daily mode, enter your start time, end time and the length of any unpaid break. The tool returns hours worked in both decimal (7.5) and HH:MM (7:30) formats, plus a weekly total assuming the same shift five days a week and a monthly estimate using 4.33 weeks per month. In weekly mode, enter the hours worked on each day separately and get a weekly total without assuming a flat schedule.
Anything above 40 hours triggers an overtime indicator. The UK Working Time Regulations cap the average working week at 48 hours over a 17-week reference period unless you have signed an opt-out. A typical UK contract is between 37.5 and 40 hours, often expressed as '9 to 5:30 with a 30-minute unpaid lunch'.
Common UK Schedule Patterns
| Schedule | Daily | Weekly Decimal | Weekly HH:MM |
|---|---|---|---|
| 9-5 with 1hr lunch | 7:00 | 35.00 | 35:00 |
| 9-5:30 with 30min lunch | 8:00 | 40.00 | 40:00 |
| 8:30-5 with 30min lunch | 8:00 | 40.00 | 40:00 |
| 7:30-4 with 30min lunch | 8:00 | 40.00 | 40:00 |
| Compressed 4x9.5hr week | 9:30 | 38.00 | 38:00 |
| 3 days at 12hr + 1 short | Varies | 37.00 | 37:00 |
Decimal vs HH:MM and Why Both Matter
Payroll runs on decimal (7.5 hours at £15 per hour = £112.50). Rotas and timesheets often use HH:MM (7:30) because it is closer to how people read a clock. Mixing them up is the single most common payroll dispute: 7.30 in a spreadsheet is seven and three-tenths of an hour, not seven hours thirty minutes. The tool shows both numbers side by side so you can copy whichever your system needs.
When invoicing in 15-minute increments, each block is 0.25 in decimal. So 6 hours 45 minutes = 6.75. Most freelancers track in 0.25 increments because it survives rounding without obvious leakage on either side.
Frequently Asked Questions
Should I deduct breaks?
If your break is unpaid (the typical UK lunch arrangement) deduct it; the calculator already does. If your break is paid, set the break field to 0. UK workers are entitled to a 20-minute break after 6 hours of work, and to 11 consecutive hours off between shifts and a 24-hour rest period each week.
How does overtime work in the UK?
There is no statutory overtime rate in the UK. Whether and how much you get for hours over 40 (or whatever your contract states as standard) depends entirely on your contract. Many salaried roles do not pay overtime at all. The 48-hour weekly cap from the Working Time Regulations applies as an average over 17 weeks, not as a hard ceiling per week.
Can I track shifts that cross midnight?
If your end time is earlier than your start time (a 22:00 to 06:00 shift, for example), enter the times as given and the tool handles the overnight roll. The figure returned is hours actually worked, not the elapsed clock time. For multi-day or rotating-shift maths, the [Date Difference Calculator](/date-difference-calculator) covers periods longer than a single day.
Why does the monthly estimate use 4.33 weeks rather than 4?
There are 52 weeks in a year and 12 months, so the average month contains 4.33 weeks. Using 4 weeks per month would underestimate annual hours by about 8%. For payroll purposes, the precise figure is calculated each month from actual working days; this calculator is for ballpark planning, not payslip generation.
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