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Time Calculator

2 hours 45 minutes plus 1 hour 30 minutes is 4 hours 15 minutes — 4.25 hours. Type each time the way you write it, add as many as you need, or start from a clock time.

Read 2-part entries like 3:45 as
Times1:30 · 1:30:15 · 1h 30m · 90 min · 1.5h

= 2 h 45 min

= 1 h 30 min

Tap + or − to add or subtract a row. A number on its own is read as minutes. With a start time, each row shows the clock after that step.

Total

4:15:00

Days, hours, minutes
4 h 15 min
Decimal hours
4.25
Minutes
255

2 times · 2-part entries read as hours:minutes

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How to add and subtract time

  1. Type one time per row, the way you would write it: 1:30, 1:30:15, 1h 30m, 1 hour 30 minutes, 90 min, 1.5h, 45s or 2d 3h. A number on its own is read as minutes.
  2. Tap + or − in front of a row to add or subtract it.
  3. Read the total as hours:minutes:seconds, in days, hours and minutes, as decimal hours and in minutes. Each row shows how it was read, so a typo is caught straight away.

Totals are never cut off at 24 hours: a week of shifts adds up to 36:20:00, not 12:20.

Example Total Decimal hours
2:45 + 1:30 4:15:00 4.25
10:20:30 − 3:45:50 6:34:40 6.58
1d 20h + 8h 30m 52:30:00 (2 d 4 h 30 min) 52.5
7:45 + 8:15 + 6:30 + 8:00 + 5:50 (a work week) 36:20:00 36.33

For the hours between a start and an end time with breaks, use the hours calculator.

h:mm or m:ss: reading 3:45

A two-part time is ambiguous: on a timesheet 3:45 means 3 hours 45 minutes, on a video or a race clock it means 3 minutes 45 seconds. Pick how two-part entries are read with the switch above the list:

You type Read as h:mm Read as m:ss
3:45 3 h 45 min 3 min 45 s
12:30 12 h 30 min 12 min 30 s
1:02:10 1 h 2 min 10 s 1 h 2 min 10 s

Three-part times are always hours:minutes:seconds. Clips of 3:45, 12:30, 7:15 and 1:02:10 add up to 1:25:40 in m:ss mode.

What time will it be? Start at a clock time

Enter a time in Start at and the list becomes a schedule: each row shows the clock after that step, and the card lists every step.

Step Duration Clock after it
Start — 9:00 AM
Welcome 45 min 9:45 AM
Workshop 1 h 30 min 11:15 AM
Break 15 min 11:30 AM
Panel 2 h 1:30 PM

Past midnight the clock says next day (or 2 days later): 3:07:15 PM plus 10 hours 58 minutes is 2:05:15 AM the next day, and 9:30 AM minus 10 hours 45 minutes is 10:45 PM the day before. A day here is 24 hours; for trips across time zones or the nights the clocks change, use the time duration calculator.

Time units and conversions

Unit In seconds In minutes In hours
1 minute 60 1 0.0167
1 hour 3,600 60 1
1 day 86,400 1,440 24
1 week 604,800 10,080 168

1 min = 60 s, 1 h = 60 min = 3,600 s and 1 d = 24 h = 86,400 s are the definitions in the NIST Guide to the SI. Months and years are not fixed lengths of time, so the calculator does not use them — count calendar months with the date calculator.

Adding time in Excel and Google Sheets

  • Type times as 2:45 and add them with =SUM(A1:A5).
  • Format the total as [h]:mm (Excel) or [h]:mm:ss (Google Sheets: Format → Number → Custom). Without the brackets, totals over 24 hours lose the whole days.
  • Decimal hours: =SUM(A1:A5)*24.
  • For minutes and seconds (video clips), enter 0:3:45 so the sheet does not read 3:45 as hours.

Adding time by hand

Add each unit separately and carry over, as with column addition:

  1. Seconds: 15 + 50 = 65 s = 1 min 5 s → write 5, carry 1 minute.
  2. Minutes: 20 + 45 + 1 = 66 min = 1 h 6 min → write 6, carry 1 hour.
  3. Hours: 10 + 3 + 1 = 14.

So 10:20:15 + 3:45:50 = 14:06:05. To subtract, borrow 60 instead: 10:20:30 − 3:45:50 borrows a minute (30 + 60 − 50 = 40 s) and an hour (19 + 60 − 45 = 34 min), leaving 6:34:40.

Frequently asked questions

How do I add hours and minutes?

Add the minutes, carry every 60 minutes into an hour, then add the hours. 2:45 + 1:30: 45 + 30 = 75 minutes = 1 hour 15 minutes, and 2 + 1 + 1 = 4 hours, so 4:15. In the calculator, type each time on its own row.

How do I add up video lengths?

Switch 'Read 2-part entries' to m:ss, then type each clip as it appears on screen: 3:45, 12:30, 7:15 and 1:02:10 add up to 1:25:40. Three-part times are always hours:minutes:seconds.

What time will it be in 2 hours and 45 minutes?

Enter the current time in 'Start at' and 2h 45m as a row. From 3:00 PM it is 5:45 PM. Add more rows to build a schedule — the calculator shows the clock after each step and says 'next day' when it passes midnight.

How do I subtract time?

Tap + next to a row to turn it into −. 10:20:30 − 3:45:50 is 6:34:40. If you subtract more than you add, the total is shown with a minus sign.

How do I convert hours and minutes to decimal hours?

Divide the minutes by 60 and add them to the hours: 36 hours 20 minutes is 36 + 20/60 = 36.33 hours. The calculator shows the decimal next to the h:mm:ss total.

Why does my spreadsheet show the wrong total over 24 hours?

Excel and Google Sheets store times as fractions of a day, and the usual h:mm format shows only the part left after whole days — 36:20 appears as 12:20. Format the total cell as [h]:mm (Excel) or [h]:mm:ss (Sheets) to see all the hours.

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