Add and subtract a list of durations, or turn hours and minutes into decimal hours. Runs on your device.
To add and subtract time, write each duration on its own line, put a minus sign in front of the ones to take away, and read the total in hours, minutes and seconds. The page opens with four lines: 1:30, + 2:45, + 0:50:30 and - 0:20. Their total is 4:45:30, which is 4 hours 45 minutes 30 seconds, 4.7583 decimal hours, 285.5 minutes or 17,130 seconds. A line with no sign is added, so a plus is optional. A table under the total shows the running total after every line, which makes a wrong line easy to spot.
A pair with a colon is hours and minutes: 1:30 is 1 hour 30 minutes, and 1:30:45 is 1 hour 30 minutes 45 seconds. Words and letters work too: 1h 30m, 90 min, 2.5 hours, 45s and 1d 2h are all read. A day counts as 24 hours. Minutes and seconds written with a colon stop at 59, so 0:90 is rejected with the line number; write 1:30 or 90m instead. Seconds are the smallest unit, so 0.4 seconds is rounded to the nearest whole second. Blank lines are ignored, and a plus or minus sign may have a space after it.
Decimal hours are the total seconds divided by 3600, shown to up to 4 decimals. In the second mode 7:45 becomes 7.75 hours, because 45 minutes is 0.75 of an hour. Likewise 8:20 is 8.3333, and 0:10 is 0.1667. Timesheets and pay sums usually want this form: 7.75 hours at a rate of 20 per hour is 155. The third mode goes the other way, turning decimal hours into hours, minutes and seconds, so 7.75 becomes 7:45:00 and 2.5 becomes 2:30:00. In both modes a column of lines gives a column of answers you can copy.
These are lengths of time, not times of day. There is no am or pm, no date, no time zone and no wrap at midnight, so 20:00 plus 6:00 is 26:00:00 rather than 02:00 the next day. To count the hours between a start and an end time, or to add hours to a clock time, use the time duration calculator. For a week of shifts with breaks and overtime, use the time card calculator. The page accepts up to 1,000 lines of at most 60 characters, and up to 100,000 hours on one line. A bad line stops the sum and the message says what is wrong, usually with the line number, so a wrong total is never shown.
Put each time on its own line. 2:45 and 1:30 add up to 4:15, which is 4 hours 15 minutes. Minutes above 59 carry into hours, so 0:45 plus 0:45 is 1:30, and the table shows the running total after each line.
Start the line with a minus sign. A first line of 5:00 and a second line of - 1:45 gives 3:15. If the total goes below zero the result carries a minus sign, as in -0:15:00, so you can see by how much you are over.
Choose Hours:minutes to decimal and type 7:45. The 45 minutes divided by 60 is 0.75, so the answer is 7.75 hours. In the same way 8:20 is 8.3333 and 0:10 is 0.1667. Decimals are rounded to 4 places.
Type 450m or 450 min on a line in the add mode. The total is 7:30:00, because 450 minutes is 7 hours and 30 minutes. A larger figure works the same way: 1500 min is 25:00:00, and hours do not wrap at 24.
Not here. This page adds lengths of time, so 10:30 is read as 10 hours 30 minutes, and there is no am, pm or midnight wrap. The time duration calculator has an Add or subtract time mode for a time of day.
The durations are processed in your browser and are not uploaded. Only your choice of mode is saved on this device, never the lines you type. Clear removes the lines and Reset puts the example back.