How to use Hours Calculator
The hours calculator computes the total time between two times of day, supporting overnight shifts, optional break deduction and multi-day durations. It also calculates weekly totals across multiple shifts, converts the result to decimal hours and shows an earnings estimate if you provide an hourly rate — making it practical for timesheet completion and payroll.
- Enter a start time and end time (12-hour or 24-hour format).
- Optionally enter break duration in minutes to deduct.
- Add multiple shifts for a weekly total.
- Optionally enter an hourly rate to see earnings.
Your data never leaves your device — 100% private processing.
Overnight shifts and 24-hour arithmetic
When the end time is before the start time (e.g. 22:00 to 06:00), the calculator automatically adds 24 hours to the end time to give the correct 8-hour result rather than −16 hours. This handles night shifts, bartenders, healthcare workers and other overnight workers correctly.
Worked examples
Standard shift with lunch
Inputs: 9:00 AM–5:30 PM minus 30 min lunch
Result: 8.0 hours
Overnight shift
Inputs: 10:00 PM–6:00 AM minus 30 min break
Result: 7.5 hours
Glossary
- Decimal hours
- Time expressed as a decimal fraction, e.g. 7.5 hours instead of 7 hours 30 minutes.
- Overtime
- Hours worked beyond the standard threshold (typically 8 hrs/day or 40 hrs/week) often paid at a premium rate.
- Net hours
- Worked time after unpaid breaks are deducted from gross shift duration.
- Timesheet
- A record of start and end times used for payroll, invoicing, and attendance tracking.
Related reading
Frequently Asked Questions
Why use Hours Calculator?
- Handles overnight shifts automatically when the end time is earlier than the start time
- Deducts break minutes from gross hours to give a precise net working-hours figure
- Totals multiple shifts for a complete weekly or pay-period hours summary
- Converts to decimal hours and estimates earnings when you enter an hourly rate
Common use cases
- Fill in a weekly timesheet by summing five daily start and end times at once
- Calculate net hours for an 11 pm to 7 am security-guard shift after a 30-minute break
- Estimate a freelancer's invoice total by multiplying hours worked by an hourly rate
- Check whether a nurse exceeded 40 hours before overtime rates were triggered
- Add up part-time shifts across different start and end times for a pay-run
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