12-Hour to 24-Hour Converter
Convert any time between 12-hour and 24-hour format.
10:21 PM
12-Hour
22:21
24-Hour (Military)
Formula
24-Hour Time = 12-Hour Time + 12 hours (if PM and not 12:00 PM); unchanged if AM (except 12:00 AM → 00:00)
Examples
12:00 AM = 00:00
6:00 AM = 06:00
12:00 PM = 12:00
1:00 PM = 13:00
3:00 PM = 15:00
6:00 PM = 18:00
9:00 PM = 21:00
11:00 PM = 23:00
Frequently Asked Questions
What is 10:21 PM in 24-hour time?
10:21 PM in 12-hour time is 22:21 in 24-hour (military) time.
How do I convert PM times to 24-hour format?
Add 12 to any PM hour except 12 PM itself (which stays as 12:00). For example, 3:00 PM becomes 15:00.
What does 00:00 mean in 24-hour time?
00:00 is midnight (12:00 AM), the start of the day.