Free tool · runs in your browser

Time calculator

Add up or subtract durations, and work out the time between two clock times, even across midnight.

Add or subtract durations

h m s

Total00:00:00

In minutes0

In decimal hours0

Time between two clock times

Start timeEnd time

Quick answer

Enter hours, minutes and seconds in as many rows as you need, choosing + or − for each, to get a total in HH:MM:SS, minutes and decimal hours. For shifts, enter two clock times to find the time between them; if the end is earlier than the start, the tool treats it as the next day, so 22:30 to 06:15 is 7 hours 45 minutes.

How to use it

Add your durations. Enter hours, minutes and seconds in each row, adding rows as needed.
Choose add or subtract. Set + or − on each row to get the running total.
Compare clock times. Enter a start and end time to see the gap, or the finish time after your total.

Example

Adding two durations and subtracting a break:

Input

+ 1h 45m 30s
+ 2h 30m 45s
− 0h 16m 15s

Output

Total: 04:00:00
In minutes: 240
In decimal hours: 4

Common errors and how to fix them

The shift length looks wrong: Check AM and PM in the time boxes. 10:00 to 06:00 is treated as overnight, or 20 hours.
Decimal hours look odd: 1.30 hours is not 1 hour 30 minutes. It is 1 hour 18 minutes. 1 hour 30 minutes is 1.5 hours.

Frequently asked questions

How do I add hours and minutes?

Add each part separately, then carry each 60 minutes into an hour. Enter the values here and it does that for you.

How do I convert minutes to decimal hours?

Divide by 60. So 1 hour 30 minutes is 1.5 hours and 45 minutes is 0.75. Payroll systems often need this form.

How do I calculate hours worked?

Enter your start and end times, then subtract any unpaid break by entering it as a − row. Multiply decimal hours by your hourly rate to get your pay.

What happens when a shift crosses midnight?

If the end time is earlier than the start, the end is treated as the next day and "Crosses midnight" shows Yes.

Can totals go over 24 hours?

Yes. Durations are not clock times, so 30 hours shows as 30:00:00.

Can the result be negative?

Yes. Subtracting more than you added shows a leading minus, such as -00:01:30.

Does it handle 12-hour times?

The time boxes follow your device settings and may show AM and PM. The calculation works the same either way.

Does it account for daylight saving?

No. Clock times are treated as a plain 24-hour day. A shift across a clock change will be an hour off.

How do I add up weekly work hours?

Add a row for each day with its hours and minutes. The total appears in HH:MM:SS and in decimal hours for payroll.

How do I find time between two dates?

This tool covers clock times within a day or overnight. For whole days between dates, use the date difference calculator.