Calculate Your Shift Hours
Enter shift times, breaks, and hourly rate to get your net hours and pay.
How the Shift Calculator Works
Four steps to calculate your shift hours and pay.
Enter Shift Times
Set your shift start and end time. The calculator handles day shifts, evening shifts, and overnight shifts automatically.
Add Breaks
Enter your total break time in minutes. Include lunch, rest periods, and any unpaid breaks that should be deducted.
Set Hourly Rate
Optionally enter your hourly rate to calculate shift earnings. Leave blank if you only need hours.
View Results
Get gross hours, net hours (after breaks), decimal hours, and shift pay computed instantly.
What Is a Shift Calculator?
Understanding shift hour calculations and break deductions.
Shift hours explained
A Shift Calculator computes the total work hours for a single work shift. It takes the clock-in time, clock-out time, and break duration to produce the net billable or payable hours.
The formula: Net Hours = (End Time − Start Time) − Break Time. A 9:00 AM to 5:30 PM shift with a 30-minute break gives you 8.0 net hours.
Types of shifts
Day shifts (6 AM–6 PM), evening shifts (2 PM–10 PM), and night shifts (10 PM–6 AM) all work the same way. The calculator detects overnight boundaries and adds 24 hours when needed.
Split shifts
A split shift has a long gap in the middle. Calculate each portion separately and add them together, or enter the full span and add the gap as break time. Subtract multiple rest periods with the break time calculator.
When to Use a Shift Calculator
Common shift calculation scenarios.
Healthcare Workers
Nurses and doctors work 12-hour shifts with mandatory breaks. Calculate net hours for accurate payroll reporting.
Manufacturing
Factory workers on rotating shifts need accurate hour counts. Track day, swing, and graveyard shifts separately.
Restaurant Staff
Calculate split shift hours for waitstaff. Lunch rush (11-2) plus dinner service (5-10) with a gap in between.
Security Guards
Night shift security from 10 PM to 6 AM. The calculator handles overnight boundaries automatically.
Delivery Drivers
Track driving hours with mandatory rest breaks. Ensure compliance with hours-of-service regulations.
Call Centers
Calculate shift coverage hours across multiple time zones. Track break compliance and net productive time.
Shift Calculation Examples
Common shift patterns and their net hours.
Standard day shift
9:00 AM – 5:30 PM, 30-min break = 8.0 net hours. The most common office shift pattern.
Night shift
10:00 PM – 6:00 AM, 30-min break = 7.5 net hours. Crosses midnight automatically.
12-hour hospital shift
7:00 AM – 7:00 PM, 60-min break = 11.0 net hours. Common in healthcare.
Part-time shift
2:00 PM – 6:00 PM, no break = 4.0 net hours. Short shifts often don't require breaks.
Step-by-Step Walkthrough
A rotating night shift priced from start to finish, including the midnight rollover that trips up most manual calculations.
A security officer works a night shift from 10:30 PM to 6:45 AM with a 30-minute unpaid break, paid at $21.40/hour.
Notice the shift crosses midnight
End 06:45 < Start 22:30 → add 24 hoursPlain subtraction gives −15h 45m, which is obviously wrong. Because a clock reading carries no date, the end time must be pushed into the following day before anything else happens.
Running totalEnd becomes 30:45
Measure the gross span
(30 × 60 + 45) − (22 × 60 + 30) = 1845 − 1350 = 495 minWith the rollover applied, the arithmetic behaves normally again. 495 minutes is 8h 15m — a plausible night shift, unlike the negative figure.
Running total495 minutes (8h 15m)
Deduct the unpaid break
495 − 30 = 465 minutesThe break sits somewhere inside the shift; exactly when does not affect the total. Only its length matters for the net figure.
Running total465 minutes net
Convert to decimal hours
465 ÷ 60 = 7.75 hoursForty-five minutes is exactly 0.75 of an hour — one of the four clean quarter-hour conversions, so no rounding is needed here.
Running total7.75 net hours
Price the shift
7.75 × $21.40 = $165.85This is base pay only. Any night-shift premium or unsocial-hours allowance is added on top, and is usually expressed as a separate rate rather than a multiplier on this figure.
Running total$165.85 base pay
A 10:30 PM to 6:45 AM shift with a 30-minute break is 8h 15m gross and 7.75 payable hours, worth $165.85 before any night premium.
Common Mistakes and Pro Tips
Mistakes that quietly corrupt your numbers
Getting a negative total for a night shift and "fixing" it by swapping the start and end times.
Add 24 hours to the end time instead: (6:45 + 24h) − 22:30 = 8h 15m.
Why it matters: Swapping the inputs happens to give the same absolute number here, but it silently reverses the meaning of the shift. On any calculation that also tracks which day the hours belong to, the swapped version attributes them to the wrong date.
Counting a night shift as belonging to the day it ended on one rota and the day it started on another.
Pick one convention — usually the start date — and apply it to every shift.
Why it matters: Inconsistent attribution makes weekly totals unreconcilable. The same shift appears in two different weeks depending on who compiled the sheet, and the error only surfaces at the week boundary where it is hardest to spot.
Applying a shift premium by multiplying the total pay by 1.2 after the fact.
Apply the premium to the hours that qualify, which may be only part of the shift.
Why it matters: Unsocial-hours premiums usually attach to specific clock windows, such as 10 PM to 6 AM. A shift running 6 PM to 2 AM has only four qualifying hours, so premium on the whole shift doubles what is owed.
Entering breaks in hours (0.5) into a field expecting minutes.
Enter 30 for a half-hour break, matching the field label.
Why it matters: Entering 0.5 deducts half a minute rather than half an hour, leaving the net figure 29.5 minutes too high. The result still looks entirely reasonable, which is exactly what makes this error survive review.
Pro tips
Flag which shifts cross midnight
Add a simple yes/no column to your rota. It makes the +24 hour adjustment auditable, and it is the fastest way to find the cause when a weekly total looks impossible.
Track premium windows separately
Night and weekend premiums usually apply to clock windows, not whole shifts. Record how many hours fell inside the window rather than tagging the shift as a whole.
Check rotating patterns as a cycle
A four-on-four-off rota does not fit a seven-day week. Verify hours across the full cycle as well as per week, or averaging rules will be applied to the wrong period.
Mind the daylight saving nights
Twice a year one night shift is genuinely an hour shorter or longer than the clock suggests. Those two shifts need manual adjustment however good the calculator is.
Keep the rate out of the hours record
Store hours and rate as separate fields. When a rate changes mid-period, a stored pay figure cannot be corrected, but stored hours can simply be repriced.
Decide about handover time
Shift handovers of 10 to 15 minutes are working time if they are required. Left out of the shift times, they vanish from pay entirely across a rota.
Common Shift Patterns and Their Net Hours
Standard rotations with a 30-minute unpaid break, showing gross span, payable hours and whether the shift crosses midnight.
| Shift pattern | Gross | Net (30 min break) | Crosses midnight |
|---|---|---|---|
| 6:00 AM – 2:00 PM (early) | 8h 00m | 7.50 | No |
| 7:00 AM – 3:00 PM (day) | 8h 00m | 7.50 | No |
| 9:00 AM – 5:30 PM (office) | 8h 30m | 8.00 | No |
| 2:00 PM – 10:00 PM (late) | 8h 00m | 7.50 | No |
| 3:00 PM – 11:30 PM (evening) | 8h 30m | 8.00 | No |
| 10:00 PM – 6:00 AM (night) | 8h 00m | 7.50 | Yes |
| 10:30 PM – 6:45 AM (night) | 8h 15m | 7.75 | Yes |
| 7:00 AM – 7:00 PM (12h day) | 12h 00m | 11.50 | No |
| 7:00 PM – 7:00 AM (12h night) | 12h 00m | 11.50 | Yes |
| 11:00 PM – 7:00 AM (graveyard) | 8h 00m | 7.50 | Yes |
No rows match that filter.
Every Yes row needs the 24-hour rollover to compute correctly — these are the shifts where manual subtraction fails. For a full week of shifts, move on to the time card calculator.
Shift Work in Practice
Rotations, premiums and the edge cases that only appear on a real rota.
Why rotating rotas need cycle-level checks
Patterns like four-on-four-off, or a three-shift continental rota, do not align with a seven-day week. Any given week may look heavily over or under contracted hours while the full cycle averages out correctly.
That is why many shift agreements define a reference period of several weeks rather than one. Checking a single week against a weekly target will produce alarming numbers that are not actually wrong.
Compute hours per shift here, then total across the complete cycle before comparing against a contract.
How shift premiums are usually structured
Three structures dominate:
- Window-based: a higher rate for hours falling between fixed times, such as 10 PM and 6 AM. Only qualifying hours attract it.
- Whole-shift allowance: a flat sum per night or weekend shift, independent of length.
- Uplifted rate: the entire shift is paid at a higher hourly rate.
The three give different answers for the same shift, so the structure matters more than the headline percentage. Enter the base rate here and apply the premium according to whichever structure your agreement uses.
The two daylight saving shifts
Once a year a night shift loses an hour and once a year it gains one. A 10 PM to 6 AM shift on the spring-forward night is genuinely seven hours of elapsed time; on the autumn night it is nine.
Clock arithmetic cannot detect this, because both readings are valid local times and the calculator has no date to reason from.
Practice varies: some employers pay the clock hours, others pay the actual elapsed hours. Either is defensible, but the decision has to be made deliberately on those two nights.
Handovers, travel and getting changed
Time spent on a required handover, on donning specialist protective equipment, or travelling between sites during a shift is frequently working time — but it sits outside the clock-in and clock-out readings, so it disappears unless recorded deliberately.
Fifteen minutes of handover per shift is roughly 65 hours a year on a five-shift week. That is not a rounding error.
If these activities are required, either include them in the shift times or record them as a separate line. Leaving them implicit means they are never paid.
Frequently Asked Questions
Common questions about the Shift Calculator.
How do I calculate shift hours?
Enter your shift start time and end time. The calculator subtracts start from end, deducts any break time, and gives you the net shift hours in both HH:MM and decimal format.
Does it handle overnight shifts?
Yes. If your shift starts at 10:00 PM and ends at 6:00 AM, the calculator correctly calculates 8 hours by detecting the overnight boundary and adding 24 hours automatically.
Can I add multiple breaks?
Enter your total break time in minutes. If you have a 30-minute lunch and two 15-minute breaks, enter 60 minutes total. The calculator subtracts all breaks from your gross shift hours.
How is shift pay calculated?
Net shift hours are multiplied by your hourly rate. If you have overtime (shift exceeds your OT threshold), those extra hours are multiplied by the overtime rate (typically 1.5×).
Can I calculate rotating shifts?
Calculate each shift individually by entering different start/end times. The tool works for any shift pattern — day, evening, night, split, or rotating shifts.
Is this shift calculator free?
Yes, free and unlimited. Rota and pay details stay on your device — the shift length and pay estimate are computed locally, with no server involved at any point.
How does the calculator handle shifts that end after midnight?
When the end time is earlier than the start time, 24 hours is added to the end before subtracting. A 10:30 PM to 6:45 AM shift correctly returns 8h 15m rather than a negative figure, so no manual adjustment is needed.
Which day do night shift hours belong to?
That is a policy decision rather than a mathematical one. Attributing the whole shift to the day it started is the most common convention and the simplest to reconcile. What matters most is applying the same rule to every shift.
Should I enter breaks in minutes or hours?
Minutes. Enter 30 for a half-hour break, not 0.5. Entering a decimal value deducts a fraction of a minute instead, which leaves the net total almost half an hour too high while still looking plausible.
Does the pay figure include a night shift premium?
No. The pay shown is base hours multiplied by the rate you enter. Night, weekend and unsocial-hours premiums are added separately, and they often apply only to the hours falling inside a defined clock window rather than to the whole shift.
What happens to shift length on daylight saving nights?
The elapsed time genuinely differs from the clock reading — one night is an hour shorter and one is an hour longer. The calculator works from clock times alone, so those two shifts a year need to be adjusted by hand according to your employer’s policy.