This time duration calculator measures how much time passes between two times of day. Enter a start time and an end time and it shows the result in hours and minutes, as decimal hours, and as a total number of minutes and seconds.
For example, a shift from 9:00 AM to 5:30 PM lasts 8 hours and 30 minutes, which is 8.5 hours.
How the Time Duration Is Calculated
The calculator converts both times into minutes from midnight, then subtracts the start from the end. The result is shown in several formats so you can use whichever one fits your task.
- Hours and minutes is the natural way to read a length of time.
- Decimal hours is what payroll and billing systems usually expect, where thirty minutes becomes 0.5 hours.
- Total minutes and seconds are handy for precise logging and exports.
Overnight and Cross Midnight Periods
If the end time is earlier than the start time, the calculator assumes the period runs past midnight into the next day. A shift from 10:00 PM to 6:00 AM is correctly counted as eight hours rather than a negative result. You can also tick the overnight option to force this behaviour.
Converting Minutes to Decimal Hours
Many timesheets need decimal hours rather than minutes. To convert, divide the minutes by sixty. Fifteen minutes is 0.25 hours, thirty minutes is 0.5 hours, and forty five minutes is 0.75 hours. This calculator does the conversion for you automatically.
What People Use It For
- Working out the length of a work shift or break
- Logging billable hours for clients
- Measuring how long a task or meeting ran
- Calculating sleep length from bedtime to wake time
- Timing study or practice sessions