Time Duration Calculator
Calculate the duration between two times in hours, minutes, and seconds, including overnight spans.
Independently verified for accuracy
Calculator by Toolsloft ↗- Duration
- 8h 30m 45s
- Total minutes
- 510.75
- Total seconds
- 30,645
Measure the duration between two times of day down to the second, shown as hours, minutes, and seconds plus running totals. Enter the times in 24-hour format, with or without seconds. Overnight durations are handled, so a span that crosses midnight is counted correctly.
How this is calculated
Both times are converted to seconds since midnight and subtracted. If the end is earlier than the start, 24 hours are added so an overnight span reads correctly; equal times give zero. The hours, minutes, and seconds are the whole-unit breakdown of the total seconds.
How to use
- Enter the start time in HH:MM or HH:MM:SS format.
- Enter the end time in the same format.
- Read the duration in hours, minutes, and seconds.
Examples
- With seconds:
09:00:00 to 17:30:45 → 8h 30m 45s - Across midnight:
23:30:00 to 01:15:30 → 1h 45m 30s
FAQ
- Do I have to include seconds?
- No. Seconds are optional. You can enter HH:MM or HH:MM:SS, and any missing seconds are treated as zero.
- How is a duration across midnight handled?
- If the end time is earlier than the start time, the tool assumes the next day and adds 24 hours, so the span is counted correctly.
- What is the difference from the hours-between tool?
- This tool works at second precision and treats equal times as zero, while the hours-between tool works in whole minutes and treats equal times as a full 24-hour span.