Hours calculator

How to find the hours between two times

Write both times in 24-hour form, then subtract the start from the end. If the end is smaller, the span crosses midnight, so add 24 hours to the end first.

Hours between = end time − start time
If the end is earlier: (end + 24:00) − start

Subtracting clock times works like subtracting money with 60 cents to the dollar. If the end minutes are smaller than the start minutes, borrow one hour as 60 minutes. 4:15 PM minus 8:45 AM is 16:15 minus 8:45: borrow to make 15:75, then 15:75 minus 8:45 is 7:30.

Worked examples

Adding and subtracting hours and minutes

Turn every line into minutes, add or subtract them, then turn the total back into hours and minutes. 3:40 is 220 minutes and 1:35 is 95 minutes; together they make 315 minutes, which is 5 hours and 15 minutes because 5 × 60 = 300 and 15 is left over.

You can type decimal hours on any line, such as 1.5 for an hour and a half, and minutes above 59, such as 90. Both are converted to minutes before anything is added, so 1.5 hours plus 45 minutes is 2:15.

A total above 24 hours is also shown in days, hours and minutes, which helps when adding up a week of shifts or a project log. To turn a total into decimal hours for payroll, use the decimal hours calculator.

Which calculator to use

• Clock times on the same day or overnight: this page, Between two times.
• Dates as well as times, such as Monday 8:00 AM to Thursday 6:00 PM: the time duration calculator, which also handles daylight saving changes.
• A shift with an unpaid lunch, or several days of work: the hours worked calculator.

Questions

Sources and method

Everything on this page is clock arithmetic: 60 minutes to the hour and 24 hours to the day. No outside rule is involved, so there is nothing to cite. The test cases behind the calculator are published with the method.

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