Time Duration Calculator
Find how many hours, minutes and seconds are between two times, including shifts and events that run past midnight. You can also add or subtract hours and minutes from a time.
Seconds are optional. Times are clock times on a 24-hour day, so the longest possible result is 23 hours 59 minutes 59 seconds. For periods longer than a day, use the Date Calculator.
- Duration
- —
- HH:MM:SS
- —
- Decimal hours
- —
- Total minutes
- —
- Total seconds
- —
How to Use the Time Duration Calculator
- Choose Time between two times, or Add or subtract time.
- To find a duration, enter the start time and the end time. Use Now to fill in the current time.
- Read the duration in hours and minutes, as HH:MM:SS, in decimal hours and in total minutes and seconds.
- To add or subtract, enter a start time and the hours, minutes or seconds to add or take away, then read the new time.
Examples
Across midnight
- Input
- Start 10:30 PM · End 1:15 AM
- Output
- Duration: 2 hours 45 minutes HH:MM:SS: 02:45:00 Decimal hours: 2.75 Total minutes: 165
Add time to a clock time
- Input
- 9:15 AM + 8 hours 30 minutes
- Output
- 5:45 PM (same day)
About the Time Duration Calculator
Working out the time between two clock times by hand is easy to get wrong, especially when minutes need borrowing or the period crosses midnight. This calculator is handy for work shifts and timesheets, sleep tracking, travel and event planning, and checking how long a recording or meeting ran.
Times are converted to seconds since midnight and subtracted. If the end time is earlier than the start time, it is treated as the next day and 24 hours are added, so 10:30 PM to 1:15 AM is 2 hours 45 minutes. Decimal hours divide the total by 3,600 seconds, which is the format many payroll and invoicing tools expect: 2 hours 45 minutes is 2.75 hours.
Both times are clock times within one 24-hour day, so durations range from 0 to 23:59:59 and daylight saving changes are not taken into account. For spans of several days, use the Date Calculator. The calculation runs in your browser with JavaScript, and this tool does not send what you enter to a Usevanta server.
Frequently Asked Questions
How do I calculate the time between two times?
Convert both to minutes (or seconds) after midnight and subtract the start from the end. If the result is negative, add 24 hours because the end is on the next day. This tool does that for you.
How do I calculate hours worked across midnight?
Enter the shift start and end as normal. When the end time is earlier than the start, the calculator counts it as the next day, so 10:00 PM to 6:00 AM gives 8 hours.
How do I convert hours and minutes to decimal hours?
Divide the minutes by 60 and add the hours. For example, 7 hours 45 minutes is 7 + 45 ÷ 60 = 7.75 hours. The calculator shows decimal hours for every result.
Does it account for daylight saving time?
No. It works with clock times only and assumes a 24-hour day, so a night when clocks change may be off by an hour.
Can it handle durations longer than 24 hours?
Not between two clock times, because a time on its own has no date. Use the Date Calculator for multi-day spans, or the add mode here, which accepts any number of hours.
Related Tools
All calculators →Count the days between two dates, or add and subtract days, weeks, months or years.
Convert a date and time between time zones, with daylight saving time handled.
A stopwatch with lap times and millisecond display that stays accurate in background tabs.
A countdown timer with presets, pause and resume, and an optional alarm sound.