Hours Calculator
Add shifts, subtract breaks, and see total time in hours, minutes, and decimal hours.
Runs in this browser. No upload by this tool. Shift and pay values are not saved.
Setup
Work shifts
Enter each shift. Breaks are subtracted from the total.
An end time before its start counts as the next day. Identical start and end times are treated as ambiguous.
Optional pay estimate
The threshold applies once across all valid rows currently entered. It is not labeled daily or weekly and does not determine legal overtime eligibility. Amounts use the same currency units as the rate you enter.
Result
Total hours
Calculated from complete, valid shifts only.
Worked time
0h 00m0.00 decimal hours
Export result
Copy the current summary or download a local file.
Creates an editable Word report locally in this browser.
Review before sharing.
How the Hours Calculator works
Use the calculator first. Then review shift arithmetic, overnight handling, decimal hours, exports, and limits.
How to calculate work hours
- Enter a shift start time and end time.
- Enter an unpaid break in whole minutes, or leave Break blank for zero.
- Add more shift rows when you want one combined total.
- Review total worked time in hours and minutes plus decimal hours.
- If useful, open Optional pay estimate and enter your own rate and overtime assumptions.
- Copy the current summary or save it locally as DOCX, Markdown, text, JSON, CSV, or through the browser Print / Save PDF workflow.
Worked examples
8:30 AM to 5:00 PM with a 30-minute break
The elapsed span is 8 hours 30 minutes. Subtracting a 30-minute break gives 8h 00m, or 8.00 decimal hours.
10:00 PM to 6:30 AM with a 30-minute break
Because the end is earlier than the start, the end is treated as next day. The elapsed span is 8 hours 30 minutes; after the break the result is 8h 00m.
7 hours 45 minutes as a decimal
Forty-five minutes is 45 / 60 = 0.75 hour, so 7h 45m = 7.75 decimal hours.
Three-shift example button
The built-in example uses 8:30-17:00 with a 30-minute break, 9:15-14:45 with a 15-minute break, and 22:00-06:30 with a 30-minute break. The combined result is 21h 15m.
What the results mean
The calculator keeps clock-time arithmetic and result formats separate so you can use the representation that fits your task.
| Result | Meaning | Example |
|---|---|---|
| Total worked time | Sum of valid shift elapsed minutes after subtracting entered breaks. | 21h 15m |
| Decimal hours | Total worked minutes divided by 60. Useful for spreadsheets and rate multiplication. | 21.25 hours |
| Break time | Sum of whole break minutes entered on valid shifts. | 1h 15m |
| Overnight shifts | Valid rows where the end clock time is earlier than the start clock time. | 22:00 to 06:30 |
| Estimated pay | Optional planning arithmetic using only the rate, threshold, and multiplier you enter. | Not a payroll or legal determination |
Hours Calculator FAQ
Does the calculator handle overnight shifts?
Yes. When a complete shift has an end time earlier than its start time, the calculator treats the end as the next day and counts through midnight.
Does the same start and end time mean a 24-hour shift?
No. Identical start and end times are ambiguous without dates, so this calculator rejects that row instead of assuming 24 hours.
How are breaks subtracted?
Enter a whole number of break minutes. The break is subtracted from the elapsed shift span. A break longer than the elapsed span is rejected.
Can I add multiple shifts together?
Yes. Add shift rows and the result totals every complete, valid row. Incomplete or invalid rows are identified and excluded from the current total.
How are decimal hours calculated?
Total worked minutes are divided by 60. For example, 7 hours 30 minutes is 7.50 hours and 7 hours 45 minutes is 7.75 hours.
Can it estimate overtime pay?
It can apply a custom threshold and multiplier across the valid rows you currently entered. Those values are your assumptions; the tool does not decide daily, weekly, or legally required overtime rules.
Does it use dates or time zones?
No. This calculator uses clock times only. It does not model calendar dates, daylight-saving transitions, time zones, or multi-day spans longer than one overnight rollover per row.
What can I export?
A valid current result can be copied or saved locally as DOCX, Markdown, TXT, JSON, CSV, or through the browser Print / Save PDF workflow.
Does the calculator save my shift data?
No. The tool does not persist shift or pay values. It runs in the current browser page and only creates files when you explicitly copy, download, or print.
Is this a payroll, labor-law, or legal calculator?
No. It performs deterministic time arithmetic and optional user-defined pay planning. Review workplace policies, payroll records, contracts, and applicable rules separately.
Method and limitations
1. Clock times become integer minutes
Each HH:MM clock value is converted to minutes after midnight. Using integer minutes avoids floating-point drift inside the shift-duration calculation.
2. Overnight rule
If the end minute is less than the start minute, 1,440 minutes are added to the end so the row crosses midnight once.
3. Same-time boundary
If start and end are identical, the row is rejected because the clock values alone cannot distinguish a zero-length span from a 24-hour span.
4. Break deduction
A whole-minute break is subtracted only after the elapsed span is known. Breaks cannot be negative or longer than the elapsed shift.
5. Decimal conversion
Total decimal hours equal total worked minutes divided by 60. The screen rounds the decimal display to two places; exported JSON keeps the minute total and a higher-precision decimal value.
6. Optional pay planning
When enabled, regular hours are capped at the custom threshold and hours above it use the custom multiplier. If no threshold is entered, all hours use the base rate.
This Tool does not use dates or time zones, determine overtime eligibility, calculate taxes or deductions, interpret labor law, validate time cards, or replace payroll records. A row can cross midnight once but cannot represent a multi-day span.
Runs in this browser. No upload by this tool. Copy/download/export locally. Review before sharing.