Add or subtract time durations, or find the exact time between two clock times — in hours, minutes and seconds, plus decimal hours for timesheets and payroll. Free, instant, and private.
How to use this time calculator
- Choose what you want: add or subtract two durations, or find the time between two clock times.
- For durations, enter hours, minutes and seconds for each time and pick Add or Subtract. For clock times, enter the start and end times with AM or PM.
- Press Calculate Time. You will see the result in plain words, in HH:MM:SS, as decimal hours, and as total minutes and seconds. Nothing you type is sent anywhere; the calculation happens on your own phone or computer.
Examples
- 2 hours 45 minutes + 1 hour 30 minutes = 4 hours, 15 minutes (04:15:00, 4.25 decimal hours, 255 total minutes, 15,300 total seconds).
- 3 hours 40 minutes − 2 hours 35 minutes = 1 hour, 5 minutes (01:05:00, 1.08 decimal hours, 65 total minutes, 3,900 total seconds).
- From 9:15 AM to 5:45 PM = 8 hours, 30 minutes (08:30:00, 8.50 decimal hours, 510 total minutes, 30,600 total seconds).
- From 10:30 PM to 6:15 AM (overnight) = 7 hours, 45 minutes (07:45:00, 7.75 decimal hours, 465 total minutes, 27,900 total seconds).
- 23 hours 30 minutes + 2 hours = 1 day, 1 hour, 30 minutes (25:30:00, 25.50 decimal hours, 1,530 total minutes, 91,800 total seconds).
What are decimal hours?
Payroll and timesheet systems usually want hours as a decimal, not as hours and minutes. You get it by dividing the minutes by 60: 45 minutes is 0.75, so 7 hours 45 minutes is 7.75 hours. Multiply decimal hours by an hourly rate and you get the pay for that time, with no manual minutes conversion.
Frequently asked questions
How is the time between two clock times calculated?
Each clock time is converted to seconds since midnight, then the start is subtracted from the end. If the end time is earlier on the clock, 24 hours are added to it first, which is how overnight spans are handled.
What if the end time is earlier than the start time?
It is treated as the next day. A shift from 10:30 PM to 6:15 AM is 7 hours 45 minutes, not a negative number.
What does a negative result mean when subtracting durations?
It means the second duration is longer than the first. For example, 1 hour minus 2 hours 30 minutes is −1 hour, 30 minutes. The minus sign is shown on purpose, so you can see the difference at a glance.
Why do payroll systems use decimal hours?
Because money maths needs a single number: 7 hours 30 minutes cannot be typed into a rate formula directly, but 7.50 hours can. Decimal hours are simply total minutes divided by 60.
Is my data stored or shared?
No. This tool works completely inside your browser. Your times are never uploaded, saved or shared.