How to use the add time calculator
- Enter the first duration in the hours, minutes and seconds boxes of the time adder. Any box can stay empty, so a 45-minute task is just 45 in the minutes box.
- Choose + Add or − Subtract for each line. Use subtract for breaks, time already used, or anything you want to take away from the total.
- Press Add time entry for as many lines as you need. The total time calculator updates as you type.
- Read the result in the format you need: h:mm:ss for stopwatch-style totals, hours and minutes for a schedule, or decimal hours for a timesheet.
Time addition by hand: adding hours and minutes
Time uses base 60, not base 10, which is why a regular calculator gets it wrong: 2.45 + 3.30 on a calculator is 5.75, but 2 hours 45 minutes plus 3 hours 30 minutes is 6 hours 15 minutes. To add hours and minutes without a tool:
- Add all the minutes: 45 + 30 = 75.
- Divide by 60: 75 minutes = 1 hour and 15 minutes.
- Add the hours, plus the carried hour: 2 + 3 + 1 = 6.
- Write the answer as 6:15.
Seconds work the same way one level down: every 60 seconds carries into one minute. This time addition calculator does the carrying for you, and as an hours and minutes calculator it also accepts values over 59, so typing 90 minutes is the same as 1:30.
Subtracting time: borrowing 60 minutes
When you subtract time and the minutes on top are smaller, borrow one hour as 60 minutes. For 5:10 − 2:35, rewrite 5:10 as 4:70, then subtract: 4 − 2 = 2 hours and 70 − 35 = 35 minutes, so the answer is 2:35. As a subtract time calculator, the tool skips the borrowing by working in seconds. If you subtract more than you added, the total is shown with a minus sign.
Worked example: totaling a day of tasks
The calculator opens with this example: a 2 hour 45 minute job, a 3 hour 30 minute job, and a 20 minute break that should not count.
| Entry | Duration | In seconds |
|---|---|---|
| + Job 1 | 2:45:00 | 9,900 |
| + Job 2 | 3:30:00 | 12,600 |
| − Break | 0:20:00 | −1,200 |
| Total | 5:55:00 | 21,300 |
21,300 seconds ÷ 3,600 = 5.9167, shown as 5.92 decimal hours or 355 total minutes.
Durations versus clock times
This page adds lengths of time, such as 1 hour 20 minutes. If you have two clock readings instead, like 8:45 AM and 3:10 PM, you need the time span between them; the hours calculator works that out, including overnight shifts. For a full week of clock-in and clock-out punches, the time card calculator totals each day and the week.
Time calculator hours as decimals for payroll
Payroll systems usually want hours as a decimal, so 5:55 becomes 5.92 rather than 5.55. The decimal total here is rounded to two places. Some employers record work time to the nearest tenth or quarter of an hour instead, a practice federal rules allow only if it does not shortchange employees over time (29 CFR 785.48(b)). To look up a single number of minutes, use the minutes to decimal chart.