Time calculator
Add or subtract two spans of time, or enter a start and an end to see the hours between them. The answer comes as hours and minutes, as a clock reading and as decimal hours.
Add or subtract two times
This answer is for the example values in the boxes above. 2 hours 30 minutes plus 1 hour 45 minutes. Change the boxes to see your own answer.
Hours between two clock times
How it works
Every time is turned into seconds, added or taken away, and turned back into days, hours, minutes and seconds. That is why 90 minutes means the same as 1 hour 30 minutes, and why a result can pass 24 hours and show a day.
The first tool adds or takes away two spans of time. Fill in hours, minutes and seconds for each, leave a box empty for 0, and choose add or subtract. The second tool starts from two clock times. Pick AM, PM or the 24-hour clock for each, and enter an unpaid break in minutes if there is one.
A worked example
Adding 2 hours 30 minutes and 1 hour 45 minutes gives 4 hours 15 minutes. The same answer is 4:15:00 on a clock, 4.25 hours, 255 minutes or 15,300 seconds. Taking the 1 hour 45 minutes from the 2 hours 30 minutes leaves 45 minutes.
A shift from 9:00 AM to 5:30 PM is 8 hours 30 minutes. With a 30-minute unpaid break it is 8 hours.
Night shifts and decimal hours
When the end is earlier than the start, the calculator counts to that time on the next day. A shift from 10 PM to 6 AM is 8 hours, and 17:30 to 01:15 on the 24-hour clock is 7 hours 45 minutes. If the start and the end are the same time, the answer is 0 hours.
Decimal hours are the hours plus the minutes divided by 60, rounded to two places in the second tool. A shift from 9:00 AM to 4:40 PM is 7 hours 40 minutes, or 7.67 hours.
What it leaves out
The calculator reads two times on a clock. It knows nothing of time zones, and nothing of the night when the clocks change, when a shift lasts an hour more or less than the clock says. Two clock times are always less than a day apart, so for longer spans use the date calculator or the days between dates calculator.
Questions
How do I add hours and minutes?
Add the minutes first and carry every 60 of them as an hour. For 2 hours 30 minutes plus 1 hour 45 minutes, 30 plus 45 is 75 minutes, which is 1 hour 15 minutes, so the total is 4 hours 15 minutes.
How do I find the hours between two times?
Take the start from the end. From 9:00 AM to 5:30 PM is 8 hours 30 minutes, and a 30-minute unpaid break leaves 8 hours of time worked.
What if the end time is earlier than the start time?
The calculator counts to that time on the next day, so 10 PM to 6 AM is 8 hours. The same time twice is 0 hours.
How do I turn hours and minutes into decimal hours?
Divide the minutes by 60 and add the result to the hours. 7 hours 40 minutes is 7 plus 40/60, which is 7.67 hours to two places.
Can I type more than 59 minutes?
Yes. Any box takes any number, so 90 minutes is read as 1 hour 30 minutes, and 25 hours is shown as 1 day 1 hour.
Is 12 AM midnight or noon?
The calculator reads 12 AM as midnight and 12 PM as noon. If a time could be read the other way, pick the 24-hour clock, where hour 0 is midnight and hour 12 is noon.
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