Time Calculator
Add and subtract hours, minutes and seconds across as many rows as you need, or find the duration between two times of day.
Total duration
0h 0m 0s
Adding and subtracting time
Time maths trips people up because it is base 60, not base 10: 90 minutes is not 1.90 hours, it is 1 hour 30 minutes. This calculator handles the carrying for you. Add a row for each chunk of time, set it to add or subtract, and the total appears in hours, minutes and seconds, plus the handy decimal-hours figure that timesheets and payroll usually want.
A worked example: a shift of 8h 30m, minus a 45m lunch, plus 20m of overtime. The rows total 8h 30m minus 0h 45m plus 0h 20m, which comes to 8h 5m, or 8.08 decimal hours, or 29,100 seconds. If the subtractions outweigh the additions the total is shown as a negative duration, so you can also use it to see how far short of a target you are.
Duration between two times
Switch to Between two times to enter a start and an end clock time. If the end is earlier than the start, the tool assumes the period runs past midnight and adds 24 hours automatically, so a night shift from 22:30 to 06:15 correctly reads as 7 hours 45 minutes rather than a negative number. Include seconds if you need that precision.
Handy conversions
- 1 hour = 60 minutes = 3,600 seconds
- 90 minutes = 1 hour 30 minutes = 1.5 hours
- 8 hours 45 minutes = 8.75 decimal hours
- 1 day = 24 hours = 1,440 minutes = 86,400 seconds
Need whole calendar dates rather than clock time? The date calculator counts days and working days between dates, and the age calculator turns a date of birth into an exact age.