Time Duration Calculator
Find the exact time difference between two clock times in hours, minutes, total hours (decimal), and total seconds.
✓ Runs in your browser · Updated 2026-03-31Enter values and click Calculate Duration to see results
How to Calculate Time Duration
The time duration calculator finds the difference between two clock times. It converts both times to minutes from midnight, subtracts, and converts back. If the end time is earlier than the start time and "crosses midnight" is checked, 24 hours are added automatically.
If overnight: Duration = (End Minutes + 1440) − Start Minutes
Decimal Hours = Total Minutes / 60
Use Cases
This tool is perfect for calculating shift durations, meeting lengths, travel times, and overtime hours. The decimal hours output is especially useful for timesheet and payroll calculations where 8 hours 30 minutes is entered as 8.50.
Overnight Shifts
Many workers — security guards, nurses, call centre agents — work shifts that cross midnight. Check the "Crosses midnight" option for these cases. The calculator will also auto-detect when end time is earlier than start time.
Related Tools
Convert between time zones with the Time Zone Converter. Count business days between dates using the Work Days Calculator.
Frequently Asked Questions
How do I calculate the time difference between two timestamps?
Enter the start and end times, and the calculator will show the difference in hours, minutes, and seconds.
Can I calculate duration across midnight?
Yes, the calculator handles overnight durations correctly. For example, from 10:00 PM to 6:00 AM gives a duration of 8 hours.
How is time duration useful for work hour tracking?
You can use it to calculate total hours worked per day or shift length, which is helpful for payroll, freelancing invoices, or timesheet submissions.