A time duration calculator for clock times and lists
It also turns views and average view duration into watch hours, shows your progress towards editable monetisation goals, and works out how long a series takes to binge. This is not a way to buy or boost watch time.
How long is a 9:15 to 17:45 shift? How many hours between 10:30 pm and 6:10 am? What do 14 video clips add up to? This time duration calculator answers both kinds of question: the time between two clock times (with optional dates for longer spans) and the sum of a list of durations, with each one added or subtracted.
Results are shown as hours, minutes and seconds, as hh:mm:ss, and as decimal hours — the format payroll, invoicing and spreadsheet formulas usually need. Overnight times are handled automatically, and everything is worked out in whole milliseconds so totals never drift.
How to use the Time Duration Calculator
- Under “Time between two times”, enter a start time and an end time. If the end is earlier than the start, the calculator assumes the period runs past midnight.
- For spans of more than a day, tick “Add dates” and pick the start and end dates.
- Read the duration in words, plus hh:mm:ss, decimal hours, total minutes and total seconds.
- To add up times, type durations into the list below, choosing + to add or − to subtract each line, and press “Add duration” for more lines.
- If you are adding song or video lengths, set “Read 1:30 as” to “1 min 30 s”. Press “Copy total” to paste the result anywhere.
Time Duration Calculator features
Overnight and multi-day
Night shifts such as 22:00–06:30 just work, and adding dates covers spans of days or weeks.
Decimal hours
Every result is also given in decimal hours (8:45 = 8.75 h) for timesheets, invoices and spreadsheets.
Flexible input
Type durations as 1:30:00, 1:30, 90m, 1h 20m 5s, 1.5h or 2d 4h — whichever is quickest.
Running total
Each line shows the total so far, so you can see exactly where a sum changes.
Watch hours and goals
Views × average view duration gives watch hours; progress bars show hours, Shorts views and subscribers against goals you can edit, with an estimate of the days left at your current pace.
Binge time
Episodes × runtime, and how many days that takes at your daily viewing time.
hh:mm or mm:ss
Switch how two-part times are read, so “3:45” can be 3 hours 45 minutes or 3 minutes 45 seconds.
How to calculate the time between two times
Convert both times to minutes after midnight, subtract the start from the end, and convert back. From 9:15 to 17:45 is 1,065 − 555 = 510 minutes, which is 8 hours 30 minutes. If the result is negative the period crosses midnight, so add 24 hours (1,440 minutes): 22:00 to 06:30 is 390 − 1,320 = −930, plus 1,440 = 510 minutes again.
With dates, the calculator counts the whole days between the two dates and then adds the difference between the clock times. It measures wall-clock time, so a night on which the clocks change for daylight saving will really be one hour shorter or longer than shown. For hours worked across a full week with breaks and overtime, the Hours Calculator builds a complete time card.
Converting minutes to decimal hours
Payroll systems and invoices often want hours as a decimal. Divide the minutes by 60: 45 minutes is 0.75 hours, so 7 h 45 min is 7.75 hours. Going the other way, multiply the decimal part by 60: 6.4 hours is 6 hours and 24 minutes. A common mistake is to write 7 h 45 min as “7.45”, which actually means 7 hours 27 minutes.
| Minutes | Decimal hours | Minutes | Decimal hours |
|---|---|---|---|
| 5 | 0.083 | 35 | 0.583 |
| 10 | 0.167 | 40 | 0.667 |
| 15 | 0.25 | 45 | 0.75 |
| 20 | 0.333 | 50 | 0.833 |
| 25 | 0.417 | 55 | 0.917 |
| 30 | 0.5 | 60 | 1.0 |
Adding times by hand
Add the seconds, minutes and hours in separate columns, then carry: every 60 seconds becomes a minute and every 60 minutes becomes an hour. For example, 1:45:00 + 0:50:30 = 1:95:30, and 95 minutes is 1 hour 35 minutes, giving 2:35:30. Subtracting 0:20:00 leaves 2:15:30 — exactly the example pre-filled in the tool. Spreadsheets can do the same if the cells are formatted as [h]:mm:ss; without the square brackets, totals over 24 hours wrap back to zero.
Where a duration calculator helps
- Shift work and freelancing: total the hours on a timesheet before multiplying by an hourly rate.
- Video and audio editing: add up clip or track lengths in mm:ss to check a running time.
- Sport and training: total lap, split or interval times, or subtract a penalty.
- Travel: add flight legs and layovers; for arrival times in another city, combine with the Time Zone Converter.
- Converting a total into days, minutes or seconds? The Time Converter handles any unit.
Time Duration Calculator FAQ
How do I calculate hours between two times?
Enter the start and end time in the time duration calculator. It subtracts one from the other and shows the answer in hours and minutes, in hh:mm:ss and in decimal hours.
How do I calculate time that goes past midnight?
Just enter the times — if the end time is earlier than the start time, 24 hours are added automatically. For example, 23:00 to 07:00 gives 8 hours. Tick “Add dates” for periods longer than one day.
How do I convert hours and minutes to decimal hours?
Divide the minutes by 60 and add them to the hours: 8 hours 20 minutes = 8 + 20 ÷ 60 = 8.333 hours. The calculator shows this as “Decimal hours” for every result.
Can I add and subtract several times at once?
Yes. Use the “Add and subtract durations” list: each line can be added or subtracted, a running total appears under every line, and the final total is shown in several formats.
Why does 1:30 show as one and a half hours?
By default two-part times are read as hours:minutes. For media lengths, change “Read 1:30 as” to “1 min 30 s” and they are read as minutes:seconds instead.
How are watch hours calculated?
Watch hours = views × average view duration in seconds ÷ 3,600. 12,000 views at 4 min 30 s is 12,000 × 270 ÷ 3,600 = 900 hours. Goals are set by the platform and can change.
Does it account for daylight saving time?
No — it measures clock time. If the clocks go forward or back during the period, the real elapsed time is one hour shorter or longer than the result.