Hours Worked With Breaks: the Two Questions the Arithmetic Cannot Answer

What the calculator computes, in full

Five inputs — start hour, start minute, end hour, end minute, break in minutes — and two outputs. Convert both times to minutes since midnight, subtract, add 1,440 if the result is negative, subtract the break, and refuse to go below zero. "Total minutes" is that number; "hours worked" is that number divided by 60. There is no third step. No rounding rule, no overtime threshold, no distinction between a paid break and an unpaid one — the break you type is always removed.

None of the five fields is validated. Type 90 into the end-minute box and it is read as 90 minutes, so 9:00 to 17:90 gives 9.5 hours. Type 25 into the end-hour box and you get 16 hours. A negative break adds time instead of removing it: 9:00 to 17:00 with a break of −30 returns 8.5 hours. And a break that is not a number at all leaves both outputs as an em dash, which is at least honest. None of this matters if you type what you mean; all of it matters if you paste a value from a spreadsheet.

The output format deserves a warning of its own. "Hours worked" is a plain decimal rendered with up to eight significant figures, so a shift of eight hours and ten minutes appears as 8.1666667. Nothing on the page converts that back into hours and minutes. If you are copying the figure into a payroll sheet that expects decimal hours, this is exactly what you want. If you are reading it to a colleague, round it yourself: multiply the fraction by 60, so 0.1666667 × 60 is 10 minutes.

Paid, and counted: two questions, not one

A break can be paid without counting as working time, and it can count as working time without anyone thinking of it as a break. The two questions come apart because they answer different things: whether the minutes go into your wage, and whether the minutes go into the ceilings — the daily maximum, the weekly maximum, the overtime threshold. A calculator that subtracts a break has silently answered the second question in one particular way.

In the United States the split is unusually clean, because the regulations say it outright. Short rest periods — 5 to about 20 minutes — are compensable and are hours worked; they may not be offset against other working time. A bona fide meal period, ordinarily 30 minutes or more, is not worktime, and only qualifies if the employee is completely relieved from duty: eating at your desk while covering the phone is not a meal period. Neither rule creates an entitlement. The FLSA requires no rest break and no meal break; what exists comes from state law, a union agreement or the contract.

In the five European markets the ordering is reversed: the entitlement is statutory and the compensation is negotiated. France sets twenty consecutive minutes as soon as daily working time reaches six hours, and makes the pause working time only when you are still at the employer's disposal — but allows an agreement to pay it anyway. Germany sets thirty minutes for more than six up to nine hours and forty-five beyond nine, splittable into blocks of at least fifteen. Spain sets fifteen minutes above six hours and, unusually, states that it counts as working time only where the agreement or contract says so. Italy sets no duration at all in the statute: the collective agreement writes it, and ten minutes is the floor if there is no agreement. Portugal is the outlier in the other direction — one to two hours, arranged so that no one works more than five hours straight.

Rounding is where timesheets actually go wrong

Nobody argues about a break of exactly thirty minutes. They argue about the four minutes between clocking in at 8:56 and the shift starting at 9:00, twice a day, five days a week. US federal regulation explicitly permits recording start and stop times to the nearest 5 minutes, or to the nearest tenth or quarter of an hour — the familiar practice behind time clocks — on the condition that it does not, over a period of time, fail to compensate employees for all the time they have actually worked. Rounding is legal; rounding that only ever goes one way is not.

The arithmetic is worth doing once, because it is larger than it feels. Quarter-hour rounding can move a punch by up to seven minutes. If it moves the wrong way at both ends of the day, that is fourteen minutes; over five days and forty-six working weeks it is 53.7 hours — more than a full working week a year, silently. Rounded fairly, the losses and gains cancel and the annual figure is close to zero. The whole legal question is which of those two things your clock is doing, and it is answerable only by comparing raw punches with the paid total over a month.

Two European provisions make the same point from the opposite side. Spain requires that working time be computed so that at both the beginning and the end of the day the worker is at their workstation — the commute to the machine is not on the clock — and separately obliges every company to keep a daily record of each worker's actual start and finish times, preserved for four years and available to the worker, their representatives and the labour inspectorate. That record is the only thing that can settle a rounding dispute, which is precisely why it exists.

The shift that crosses midnight

This is the case that breaks most home-made spreadsheets, and the tool handles it. When the end time is earlier than the start time the span comes out negative, so 1,440 minutes — one day — are added back. A shift from 10 p.m. to 6 a.m. with a 30-minute break returns 7.5 hours; 9:45 p.m. to 6:15 a.m. with 30 minutes returns exactly 8. The wrap is unconditional, which is the right choice: the tool has no date fields, so it cannot know whether you meant tonight or this morning, and assuming forward is the only assumption that ever produces a positive answer.

There is one hole in it, and it is a small one. Because the wrap only triggers on a negative span, a start equal to the end produces zero, not 1,440. Enter 9:00 to 9:00 and the tool reports an empty day. That is the correct reading nine times out of ten — you mistyped — but a genuine 24-hour on-call block, which exists in healthcare and in fire services, cannot be expressed. Enter it as two rows, or as 9:00 to 8:59 and add a minute.

The harder question the tool cannot answer is which day the hours belong to. A shift from 10 p.m. Monday to 6 a.m. Tuesday is eight hours somewhere, but whether they land on Monday's daily maximum, on Tuesday's, or are split at midnight is decided by the rule you are working under, not by arithmetic. If you are checking a daily ceiling or a night premium, decide the attribution before you total anything; the number the calculator gives you is the same either way, and only one of the two placements will be right.

A week, worked end to end

Run the five days one at a time and add them yourself; the tool has no weekly total. A shop-floor week of 6:00 to 15:30 with a 45-minute break gives 8.75 hours a day, or 8 h 45 min, and 43.75 hours over five days. An office week of 8:30 to 17:15 with the same 45-minute break gives exactly 8 hours a day and 40 over five. The difference between those two weeks is not the working day — both start early and end mid-afternoon or later — it is a single hour of daily span.

Notice what the shop-floor week triggers. Nine and a half hours on site with 8.75 worked crosses the six-hour line in every one of the six markets, and in Germany it crosses the nine-hour line too, so the required break there is 45 minutes rather than 30 — which is exactly what was entered. Change the break to 30 and the tool will happily return 9 hours a day and 45 a week, without a word. That is the whole argument for reading the statute before reading the number: the calculator will compute any week you describe to it, including one you are not allowed to work.

Frequently asked questions

Should I subtract my lunch break from hours worked?

Subtract it if you were genuinely free during it and it is unpaid. Do not subtract a short rest break: in the United States a rest period of 5 to about 20 minutes must be counted as hours worked, and offsetting it against other working time is not allowed. The awkward middle case is the meal you take at your post while remaining reachable. Under US rules that is not a bona fide meal period at all, because you were not completely relieved from duty, so it is worked time. The calculator has no opinion — whatever you type in the break box is removed.

Does the calculator handle a night shift that crosses midnight?

Yes. When the end time is earlier than the start, it adds one full day — 1,440 minutes — before deducting the break, so 10 p.m. to 6 a.m. with a 30-minute break returns 7.5 hours and 450 total minutes. The one gap is a start exactly equal to the end: that produces zero rather than 24 hours, so a genuine 24-hour block has to be entered as two rows. And note that the tool has no date fields, so it cannot tell you which calendar day the hours belong to — that matters for daily maximums and night premiums, and you have to decide it yourself.

Why does it show 8.1666667 instead of 8 h 10 min?

Because "hours worked" is declared as a plain number and the shared renderer prints numbers with up to eight significant figures. Ten minutes is one sixth of an hour, which has no finite decimal, so you get the repeating digits. The second output, "total minutes", is the one to read when you want an exact answer: 490 minutes is unambiguous where 8.1666667 is not. To convert by hand, take the part after the decimal point and multiply by 60.

Can my employer round my clock-in time?

In the United States, yes, within limits: federal regulation contemplates recording start and stop times to the nearest 5 minutes, or the nearest tenth or quarter of an hour, provided the practice does not over time fail to pay employees for all the time they actually worked. The word doing the work is "over time". Rounding that lands both ways is arithmetic noise; rounding that only ever lands in the employer's favour is underpayment dressed as arithmetic. The check is simple and worth doing once: total a month of raw punches, total the same month as paid, and see whether the gap is roughly zero or roughly one-directional.

Is a statutory break paid?

Not automatically, in any of the six markets. In the United States the answer follows from the length: a short rest period is paid because it is hours worked, a genuine meal period is not. In France, Spain and Italy the statutory break is unpaid unless a collective agreement or the contract provides otherwise, and French law spells this out twice — once to say the pause is working time only when you stay at the employer's disposal, and once to allow an agreement to pay it even when it is not working time. Germany treats the Ruhepause as an interruption of work, and Portugal's interval is likewise outside working time except where you must stay near the workplace to be recalled. So the honest answer everywhere is: read the agreement, not the statute.