To add hours and minutes, add each part separately, then turn every 60 minutes into one hour. For example, 2h30 plus 1h45 equals 4h15, rather than 3h75.
This is useful for adding study sessions, planning tasks or checking how long an activity lasted. If your period includes a break or crosses midnight, separate those details before calculating.
Calculate my hours and minutes
Add the hours, then carry the minutes
Take 02:30 plus 01:45. The hours add up to 3, while the minutes add up to 75. Since 75 minutes is 1h15, add that extra hour to the original three. The total is 04:15.
In the hours and minutes calculator, choose the duration-sum option and enter one duration per line. A colon separates hours from minutes; the minutes part must be between 00 and 59.
Calculate a start-to-end period with a break
From 09:00 to 18:00 is 9 hours. If that period includes a 60-minute break, subtract it: 9h − 1h = 8h.
- Choose the calculation between two times.
- Enter the start and end times.
- Enter the break in minutes: for example, 60 for one hour.
- Check that the result describes the period you intended.
Do not subtract a break twice. If you have already added only the active sessions, leaving the break out, that pause has already been excluded.
What if the period crosses midnight?
From 22:00 to 06:00 the next day is 8 hours: two before midnight and six after it. With a 30-minute break, the result is 7h30.
Select the next-day option in the tool. Without that detail, an end time earlier than the start can look like an incorrect entry. This example assumes an ordinary 24-hour day without time-zone or daylight-saving adjustments.
A total over 24 hours is a duration
A duration can be longer than a day. For example, 25h30 plus 2h15 is 27h45. This describes accumulated time, rather than a time of day on a clock.
Use the sum-of-durations option for that case. Comparing a start time with an end time describes one period between clock times; it is not the same as adding several days of sessions.
1h30 means 1.5 hours, not 1.30
To express minutes as a decimal fraction of an hour, divide them by 60. Thirty minutes is 0.5 hour, while fifteen minutes is 0.25. So 1h30 = 1.5 hours, and 1h15 = 1.25 hours.
Before transferring a result to a spreadsheet, check which format it expects: hours and minutes, or decimal hours. Mixing the two changes what the number means.
A quick final check
- Enter 01:45, rather than 1.45, in a duration field.
- Convert 90 minutes to 01:30 instead of entering 00:90.
- Make sure the break is shorter than the whole period.
- Check the next-day option when the period crosses midnight.
These examples help you organize durations. The calculator does not apply payroll rules, night-work premiums or employment agreements.
Calculate my hours and minutes
Unit reference: NIST Guide to the SI: minute and hour. Worked examples: InfosPixel.
