About the Time Calculator
This Time Calculator does the arithmetic on durations that is awkward to do in your head because time counts in 60s and 24s. In the first tab, list as many rows as you like, mark each one as added or subtracted, and type days, hours, minutes and seconds. You get the total as days and H:MM:SS, plus total hours, minutes, seconds and decimal hours. In the second tab, pick a start and an end clock time and see how long lies between them, with an optional break taken off. It works with durations, not calendar dates: a day is always 24 hours, with no daylight saving or leap seconds. For days between dates, use the Days Between Dates tool. Everything is worked out on your device.
Updated October 2026
How to use the Time Calculator
- 1Choose Add or subtract time, or Time between two clock times.
- 2For adding, mark each row as Add or Subtract and type the days, hours, minutes and seconds. Blank boxes count as 0.
- 3For a clock difference, pick the start and end times, tick End is the next day if needed, and enter any break.
- 4Read the total, the decimal hours and copy the result.
Adding and subtracting time
Time is awkward because it does not use tens. Sixty seconds make a minute, sixty minutes make an hour and twenty-four hours make a day, so ordinary column addition gives wrong answers. The calculator converts every row to seconds, adds or subtracts them, and turns the total back into days, hours, minutes and seconds.
Use the row selector to mix additions and subtractions in one list. This is handy for working out how much of a recording is left after cutting sections, or how much of a budget of hours remains after tasks.
Time between two clock times
The second tab finds the length of time from a start to an end on the clock, using a 24-hour day. When the end is earlier than the start, the tool counts through midnight, which suits night shifts and overnight travel. Tick End is the next day when the end is later on the clock but a day after, and when the two times are the same, that tick gives a full 24 hours.
Enter a break in minutes to remove it from the total. If the break is longer than the time available, you get a message instead of a negative result.
Decimal hours for payroll
Timesheets and invoices often want 7.5 hours, not 7 hours 30 minutes. Decimal hours are minutes divided by 60, rounded to two places, so 20 minutes is 0.33 and 50 minutes is 0.83. Note the rounding: adding rounded decimals row by row can drift by a hundredth, so add the real times first and convert once at the end. For a week of shifts with pay, our Hours Calculator builds the whole time card. To compare cities use the Time Zone Converter, and the Age Calculator works with years.
Common mistakes
- Typing 90 minutes and expecting 0.90 hours; 90 minutes is 1.5 hours.
- Forgetting that the end time is on the next day for overnight work.
- Using this tool for calendar dates. It counts durations only, so it ignores daylight saving changes and leap seconds.
- Entering decimals or negative numbers in the boxes. Each box takes whole numbers of 0 or more, and you use the Subtract setting for taking time away.
Features
- Add or subtract any number of rows
- Days, hours, minutes and seconds in every row
- Total shown as days and H:MM:SS, hours, minutes, seconds and decimal hours
- Time between two clock times, crossing midnight
- Optional break in minutes
- Negative totals shown clearly
- Copy the result in one tap
Frequently asked questions
How do I add hours and minutes?
Type the hours and minutes of each time on its own row and leave the mode on Add. For example 1 h 30 min plus 2 h 45 min gives 4:15:00. The tool carries minutes into hours for you, so you never have to work out that 75 minutes is 1 hour 15.
How do I subtract times?
Set a row to Subtract. Enter the larger time on an Add row first, then the time you want to remove on a Subtract row. 10 hours minus 45 minutes 30 seconds is 9:14:30. If you take away more than you started with, the total shows a minus sign.
How do I calculate the hours between 10 pm and 6 am?
Open Time between two clock times, enter 22:00 as the start and 06:00 as the end. Because the end is earlier than the start, the tool counts across midnight and shows 8 h.
How do I turn minutes into decimal hours?
Divide the minutes by 60. Thirty minutes is 0.5 hours, and 45 minutes is 0.75. The result panel shows decimal hours to two places, which is the format many payroll and invoice systems ask for.
Can I add days too?
Yes. Every row has a Days box, and a day is counted as exactly 24 hours. A total of 90,061 seconds shows as 1 day 1:01:01. For dates on a calendar, such as the days between two dates, use the Days Between Dates tool instead.
How do I add several times together?
Press Add row for each extra time. There is no fixed limit, so you can total a week of shifts or a list of video lengths. Remove row deletes the last one, and the total updates as you type.