What does an hours calculator do?
An hours calculator finds the amount of time between two clock times, and adds several such spans into a total. That is the whole job, and it is done properly in two places where hand arithmetic usually is not: subtracting an unpaid break, and handling a shift that runs past midnight. Give it a start time, an end time and a break, and it returns the hours and minutes worked, the same figure in decimal hours, and the gross pay if you supply a rate.
Several shifts can be entered at once, which is what turns it from a single subtraction into a timesheet. Each row is independent, the total is summed across all of them, and the decimal figure is what payroll systems actually multiply by the rate. The distinction between hours-and-minutes and decimal hours is the one most often got wrong by hand: seven hours and thirty minutes is 7.50 in decimal, not 7.30, and using the wrong one understates a day's pay by twenty minutes' worth.
The calculator deliberately stops at the arithmetic. It does not know your contract, so overtime thresholds, paid breaks, night-shift supplements, weekend rates and statutory holiday entitlements are all outside its scope — as is any deduction, tax or contribution. The total it produces is the raw time worked, which is the input those rules need and not a replacement for them.
How to calculate hours worked
- Enter the start and end time of the first shift. Overnight shifts are handled: an end time earlier than the start is read as the next day.
- Put the unpaid break in minutes — a thirty-minute lunch is 30, not 0.5. It is subtracted from the shift length.
- Press Add another shift for each further day, and the running total updates as you type.
- Read the two totals: hours and minutes for the schedule, and decimal hours for the payroll system.
- Optionally enter an hourly rate. The gross pay figure is the decimal hours multiplied by that rate, before any deduction.
- Reset before starting a fresh week, since the tool has no memory of past entries and does not save anything.
Hours Calculator limits and rules
| Item | Limit |
|---|---|
| Shifts | As many rows as you need, each with its own break |
| Break | Entered in whole minutes and subtracted from the shift |
| Overnight | An end time before the start is treated as the following day |
| Outputs | Hours and minutes, decimal hours, shift count and gross pay |
| Rate | Optional, used only to multiply out a gross figure |
| Time zone | Irrelevant — the calculation is between two clock times on one day |
| Not modelled | Overtime, paid breaks, shift premiums, tax, deductions and holiday entitlement |
| Shifts over 24 hours | Not supported; each row is a single day's span |
When to use it
- Totalling a week of shifts from a handwritten clock-in sheet before submitting it.
- Checking a payslip by working out the hours it should have been calculated from.
- Converting hours and minutes into decimal hours for a form that demands the latter.
- Working out how long a task, a drive or an event actually took, and how much to charge for it.
- Adding up freelance hours across several clients to invoice each one separately.
Is it private?
The arithmetic runs in your browser and nothing is submitted, so no timesheet, rate or pay figure is sent anywhere. There is no account and no stored history; closing the tab discards everything.
Frequently asked questions
Because decimal hours divide the minute figure by sixty, not by a hundred. Thirty minutes is half of an hour, so it is 0.50; forty-five minutes is three quarters, so 0.75. Writing 7.30 would mean seven hours and eighteen minutes, which is why the two figures are never interchangeable. Payroll systems multiply the hourly rate by decimal hours, so this conversion is not a stylistic choice — using the wrong number changes the amount paid.
By adding a day when the end time is earlier than the start. A plain subtraction of 20:00 from 04:00 gives minus sixteen hours, which is nonsense as a duration. The tool reads that combination as a shift that ran past midnight and computes it as eight hours instead. What it cannot detect is a shift of more than twenty-four hours, since a row is one start time and one end time; for a span that long, split it across two rows.
Only unpaid ones, and that is a question about your contract rather than about arithmetic. Many jurisdictions require a rest break after a certain number of hours and allow it to be unpaid, which is the case the field is built for. If your breaks are paid, leave the field at zero and the shift length stands as it is. Getting this backwards is one of the commonest causes of a timesheet that disagrees with a payslip by half an hour a day.
No, and it deliberately does not try. Overtime rules differ by country, by industry and by contract: some apply after forty hours in a week, some after eight in a day, some only after six consecutive days, and the rates and exemptions differ again. None of that can be inferred from a list of clock times. Enter each shift here to get the hours, then apply your own overtime rule — or use a payroll system that knows it.
Yes, and the pay field is really a billing field in that case: enter your hourly rate and the gross figure is what to invoice at that rate, before tax. The caution is the same one, with one addition: billable hours are often not the same as hours worked, since some clients round to the nearest quarter hour, some have a minimum billing period, and some treat travel or waiting time differently. Round the figures to whatever your agreement says before sending the invoice.
Almost always because one of the time fields is empty or its break is larger than the shift itself. An empty start or end time produces a dash in that row rather than a number, and the total ignores incomplete rows. A break longer than the shift is floored at zero rather than producing a negative duration. Check the individual row figures first: if a row shows a value and the total looks wrong, the row is not the problem.
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Written and maintained by Md. Nur Hossain Repon.