How to Use the Time Duration Calculator
Enter two times to find the duration between them, or enter a time and a duration to add or subtract — the calculator handles the base-60 minute math and 12-hour or 24-hour format automatically, returning a correctly simplified result.
The Time Duration Calculator handles the base-60 arithmetic automatically — here's how to use it for a few common scenarios.
Finding a duration between two times
Enter a start time and an end time to see the exact duration between them — the calculator correctly handles any noon/midnight boundary crossing without requiring manual AM/PM tracking.
Adding or subtracting a duration
Enter a starting time and a duration to add or subtract (hours and minutes) to find the resulting time — useful for planning a schedule, calculating an end time from a start time and expected length, or working backward from a deadline.