Time Calculator

Add or subtract time durations in days, hours, minutes, and seconds. Convert between time units.

How to Calculate

1 day = 24 hours = 1,440 minutes = 86,400 seconds

Time uses a base-60 system for minutes and seconds, and base-24 for hours. When adding, carry over when a unit reaches its maximum (60 seconds → 1 minute, 60 minutes → 1 hour, 24 hours → 1 day).

Frequently Asked Questions

How do I add time?
Add each unit separately (days, hours, minutes, seconds), then carry over: 60 seconds = 1 minute, 60 minutes = 1 hour, 24 hours = 1 day.
How do I convert hours to decimal?
Divide the minutes by 60 and add to the hours. For example, 2 hours 30 minutes = 2 + 30/60 = 2.5 decimal hours.