Time calculations help you add or subtract time periods for various applications.
Common Uses:
Time Conversion:
Calculation Tips:
This calculator works with 24-hour time format and handles time arithmetic across day boundaries.
Type start and end times using hours, minutes, and seconds. The calculator accepts both 12-hour (AM/PM) and 24-hour formats.
Choose to add a duration (e.g. 2h 30m) to a starting time, or subtract a duration to find the earlier time. We handle day rollover automatically.
See the answer in hours, minutes, seconds, decimal hours, and total seconds. Perfect for payroll, billing, and time tracking.
For related calculations, try our hours calculator.