Time Duration Calculator
Enter a start and end time and get the exact duration in hours, minutes, and seconds. It handles overnight spans too, so night shifts and cross-midnight travel times work fine.
How to use
- Enter your start time - you can use 24-hour format or AM/PM, either works.
- Enter the end time the same way.
- If the end time is earlier than the start time, it automatically assumes you crossed midnight.
- Hit Calculate for the duration in hours, minutes, and seconds.
Related tools:
Working out how long something took is surprisingly fiddly when it crosses the top of the hour or spans multiple sessions. If you started at 9:40 AM and finished at 4:15 PM, that is 6 hours 35 minutes - not immediately obvious without doing the subtraction. Overnight sessions (starting 11 PM, ending 6 AM) add another layer.
The calculator handles all of it: enter a start and end time and get the exact duration in hours, minutes, and seconds. You can add multiple time ranges and get a total - useful for freelancers calculating billable hours across several work sessions in a day, or tracking time split across multiple tasks.
Frequently Asked Questions
Does it handle overnight durations?
Yes. If the end time is before the start time, the calculator assumes the end is on the next day. 11:30 PM to 7:00 AM gives 7 hours 30 minutes.
Can I enter time in 24-hour format?
Both 12-hour (AM/PM) and 24-hour formats are typically accepted. Check the input format the tool uses - entering 14:30 or 2:30 PM should both work.
How do I calculate total hours worked across a week?
Add each day session separately and sum the totals. Enter start and end time for each day (minus breaks), and add the durations together for a weekly total.