Time Calculator

How to Calculate Time Difference

Calculating the difference between two times is useful for tracking work hours, travel duration, cooking times and more. The simplest method is to convert both times to minutes from midnight, find the difference, then convert back to hours and minutes. For example, the difference between 09:30 and 14:15 is: (14 x 60 + 15) - (9 x 60 + 30) = 855 - 570 = 285 minutes = 4 hours 45 minutes.

Adding and Subtracting Time

To add time, simply add the hours and minutes separately, then adjust if minutes exceed 60. For example, 10:45 + 2 hours 30 minutes: 10+2 = 12 hours, 45+30 = 75 minutes = 1 hour 15 minutes, so the result is 13:15. Subtracting works similarly but in reverse. This calculator handles all the carry-over arithmetic automatically.

12-Hour vs 24-Hour Clock

The 24-hour clock (also called military time) runs from 00:00 to 23:59, eliminating AM/PM confusion. The 12-hour clock uses AM (midnight to noon) and PM (noon to midnight). This calculator uses the 24-hour format for input and shows the result in both formats. To convert: PM times add 12 to the hour (except 12 PM stays 12), and AM times stay the same (except 12 AM becomes 00).

Frequently Asked Questions

How do I calculate my work hours?

Use the "Time Difference" mode. Enter your start time (e.g. 09:00) and end time (e.g. 17:30). The calculator will show the duration as 8 hours and 30 minutes. If you take a lunch break, calculate the morning and afternoon sessions separately and add them.

Can I calculate time across midnight?

Yes. If your end time is earlier than your start time, the calculator assumes the end time is on the next day. For example, from 22:00 to 06:00 gives a duration of 8 hours.

What are common use cases for a time calculator?

Common uses include calculating work hours and overtime, planning travel itineraries with time zone changes, tracking exercise or study durations, scheduling meetings across different times, and computing cooking or baking times.