Date & Time Calculators
Hours Calculator
Calculate hours between two times.
Enter the values and review the result.
Enter start time (e.g., 09:00 AM).
Enter end time (e.g., 05:00 PM).
Subtract lunch or break time.
Calculation assumptions
- *Start and end times can use 24-hour format or AM/PM format.
- *If the end time is earlier than the start time, the calculator treats it as an overnight shift.
- *Break time is subtracted in minutes and cannot be negative.
- *This is a time-tracking estimate, not a payroll rules engine.
Enter your values and press Calculate.
Results and breakdowns will appear here after a valid calculation.
How work hours are calculated
The calculator converts your start and end clock times into minutes, finds the elapsed time, then subtracts any break duration.
Example: 9:00 AM to 5:00 PM is 8 hours. With a 60-minute break, the total work time is 7 hours.
If the end time is earlier than the start time, the calculator assumes the shift crossed midnight.
Common mistakes
- Entering a negative break instead of zero.
- Forgetting to include lunch or unpaid breaks.
- Using ambiguous times without AM/PM when 24-hour format would be clearer.
- Expecting overtime, rounding, or payroll policy rules to be applied automatically.
Transparency note
Accuracy and limitations
Calzivo tools are built for practical estimates, conversions, and checks. Some tools use standard formulas or simplified assumptions, and results can be affected by input accuracy, rounding, units, local rules, or changing official requirements.
Results depend on the values you enter and any simplified assumptions used by the tool. Verify important results before making decisions or submitting official information.
How to Use This Tool
Use these steps to enter the right inputs and interpret the result correctly.
Enter your start time and end time, such as 09:00, 17:00, 9:00 AM, or 5:00 PM.
Enter any break duration in minutes.
The calculator will show your total work hours.
Decimal hours are also provided for payroll purposes.
Related Tools
Other helpful tools in the Date & Time Calculators category.
Time Calculator
Add or subtract time durations.
Workday Calculator
Calculate business days between dates.
Date Difference Calculator
Find the number of days between two dates.
Days Between Dates Calculator
Count the exact days between any two dates.
Time Zone Converter
Convert time between different cities.
Related Guides
Background reading and explanations related to Hours Calculator.
Frequently Asked Questions
Common questions about Hours Calculator and how to read the result.
Does it work for overnight shifts?
Yes, if the end time is earlier than the start time, the calculator assumes the shift ended the next day.
What time formats are supported?
You can enter 24-hour times such as 17:00 or AM/PM times such as 5:00 PM.
Can break time be negative?
No. Break duration must be zero or a positive number of minutes.
Does this calculate overtime?
No. It calculates elapsed work time after breaks. Overtime rules depend on employer policy and local law.
What are decimal hours?
Decimal hours express minutes as part of an hour, such as 7.50 hours for 7 hours 30 minutes.
Can I use this for payroll?
Use it as a planning check only. Confirm rounding, overtime, and break rules with your employer or payroll system.