Hours Calculator

weekly hours = each of the seven days measured as end − start, plus 24 hours on any day whose end time is earlier; then the break is subtracted once for every day worked, never by more than that day's shift

start

When the shift began, as a 24-hour clock time such as 09:00. A day with both boxes empty is a day off

end

When the shift ended. An end earlier than the start is read as the next morning, so 06:00 after a 22:00 start is eight hours, not sixteen hours backwards

break

The unpaid break deducted from every day worked, in minutes or hours. One figure covers the whole week

weeklyHours

The headline result: the week with breaks taken out. This is the number a timesheet and a payroll system use

grossHours

The same week with nothing deducted, for checking the total against the shift lengths

breakHours

Everything that came off, added up across the days worked. It can be smaller than the break multiplied by the days worked — see the limitation on long breaks

daysWorked

How many of the seven days had both times filled in. A day you cleared entirely is not counted, and neither is a day you were off

Use it to close out a week on a timesheet, to check a payslip against the shifts you actually worked, or to price a job by the hour. It answers "how much time went in", not "what is it worth" — overtime rates, shift premiums and holiday pay are a payroll rule, not an arithmetic one, and they change by employer and by country. If you need a single shift rather than a week, or a shift that spans midnight twice, the numbers are here for the taking: the weekly figure is just the seven days added up, so one filled-in day gives that one day's net hours.

1. Five standard days with a 30-minute break

   1. Each weekday runs 09:00 to 17:30, which is 8.5 hours, so the five of them come to 42.5 hours before breaks
   2. The break is 30 minutes a day, so five days cost 2.5 hours in total
   3. 42.5 − 2.5 = 40 net hours, which is exactly the 40-hour week the five days were meant to add up to
   4. The whole hours are 40 and there are no minutes left over, so the second and third rows read 40 and 0

   This is what a full-time week looks like once the lunch break is taken out: five 8.5-hour days are 42.5 hours of presence, and the 2.5 hours of breaks bring it back to 40.

2. The same week plus a four-hour Saturday

   1. The five weekdays still give 42.5 hours, and Saturday 10:00 to 14:00 adds 4 hours, so 46.5 hours before breaks
   2. The break comes off six days now, not five: 6 × 30 minutes = 3 hours
   3. 46.5 − 3 = 43.5 net hours
   4. 43.5 hours is 43 whole hours and 30 minutes, so the two text rows read 43 and 30 while the headline reads 43.5

   Whether hours past 40 are paid at a premium is not something this page decides — it counts the time, and the 43.5 is the figure a payroll rule would then be applied to.

3. Five night shifts running past midnight

   1. 06:00 is earlier than 22:00, so each shift is read as crossing midnight: 2 hours to midnight plus 6 hours after it, which is 8 hours
   2. Five such nights are 40 hours before breaks — the same gross total as five ordinary days, from entirely different clock times
   3. Five 30-minute breaks take off 2.5 hours, leaving 37.5 net hours
   4. 37 whole hours and 30 minutes left over, which is the same span written two ways

   Reading the pair as an overnight shift is the only interpretation that makes sense here; the alternative (a 16-hour-negative shift) would make the weekly total collapse. Nights that start and finish on the same clock time, such as 22:00 to 22:00, count as zero rather than as a full day.

The break is one figure for the whole week, so a week where Tuesday had an hour off and the rest had thirty minutes cannot be entered as it stands — deduct the fixed part here and add the difference by hand, or run the long day as its own calculation. A break longer than the shift it belongs to is clamped to that shift rather than producing negative hours, which means the break total can be smaller than the break multiplied by the days worked. Only whole clock times are accepted: there is no way to enter a shift that starts at 09:00:30, and no way to enter a shift longer than 23 hours 59 minutes, because every day is a pair of times rather than a start and a finish date. Public holidays, paid leave and overtime rates are not part of this figure at all.

How do I add up a week of hours?

Fill in a start and an end time for each day you worked and the hours calculator totals the seven days, then subtracts the unpaid break once per day worked. Five 09:00-to-17:30 days with a 30-minute break come to 40 net hours. Leave both boxes of a day empty if you were off — that day contributes nothing and drops out of the days worked.

What counts as a full working week?

Forty hours is the usual benchmark, and it is a legal one in several countries rather than a custom. Under the Fair Labor Standards Act in the United States, hours worked beyond forty in a workweek must be paid at not less than one and a half times the regular rate, which is why the weekly total is the number that matters rather than the daily one. Five 8.5-hour days with a half-hour break land exactly on forty; anything longer is overtime hours under that rule.

How do I enter a shift that runs past midnight?

Type the times as they appear on the clock and let the earlier end time do the work: an end time earlier than its start is read as crossing midnight, so 22:00 to 06:00 is 8 hours. Do not add 24 hours or convert to 24-hour-plus notation — 22:00 to 06:00 typed as it stands gives the right answer. A shift that ends at the same time it starts, 22:00 to 22:00, counts as zero rather than as a full day.

Why does clearing one time box show an error?

Because an empty day means a day off, so half an empty day is ambiguous and the page refuses to guess. Clear both boxes of that day to mark it as not worked, or fill both to count it. Silently skipping a half-filled day would be worse: the week would come out eight hours short and nothing on the page would look wrong.

What if the break is longer than the shift?

The break is capped at the length of that day's shift, so a two-hour break on a one-hour shift leaves that day at zero rather than at minus one hour. Only the capped amount is deducted, which is why the break total can come out lower than the break multiplied by the days worked. A day whose two times are identical also counts as zero net hours but still counts as a day worked.

• 29 U.S.C. § 207 — Maximum hours and overtime compensation — Legal Information Institute, Cornell Law School
• 29 C.F.R. § 785.19 — Meal periods — Office of the Federal Register
• ISO 8601: International Standard Date and Time Notation — Markus Kuhn, University of Cambridge