24-Hour Time Converter
A 24-hour time converter translates between the 12-hour AM/PM clock and the 24-hour (military) time format. Enter a time in either format in the panel to convert instantly. The current time is shown below in both formats for quick reference.
What Is the 24-Hour Clock?
The 24-hour clock is a timekeeping convention that counts the hours of the day from 0 to 23, beginning at midnight (00:00) and ending just before the next midnight (23:59). Unlike the 12-hour clock, which resets at noon and requires AM and PM designations to distinguish morning from afternoon, the 24-hour system is unambiguous. Each time of day has exactly one representation. A time like 14:30 can only mean 2:30 in the afternoon, not 2:30 in the morning.
The 24-hour clock is the standard time format used in most countries outside the United States, and it is the default in scientific, medical, transportation, and military contexts worldwide. The time clock converter can help with additional time format conversions related to work and payroll.
How to Convert 12-Hour to 24-Hour Time
AM Conversions
For AM times from 1:00 AM to 11:59 AM, the conversion is straightforward: keep the hour as-is and drop the AM designation. 1:00 AM becomes 01:00, 9:30 AM becomes 09:30, and 11:45 AM becomes 11:45. The only exception is 12:00 AM, which represents midnight and converts to 00:00, not 12:00.
PM Conversions
For PM times from 1:00 PM to 11:59 PM, add 12 to the hour. 1:00 PM becomes 13:00, 5:30 PM becomes 17:30, and 9:15 PM becomes 21:15. 12:00 PM (noon) is the only PM exception: it remains 12:00 in 24-hour format because noon is the 12th hour, not an addition to it.
Midnight and Noon
Midnight (12:00 AM) converts to 00:00 in 24-hour time. Noon (12:00 PM) stays 12:00. These two are the most commonly confused conversions. A quick rule: 12 AM = 00:00, 12 PM = 12:00. Every other PM time = hour + 12.
How to Convert 24-Hour to 12-Hour Time
To convert from 24-hour to 12-hour time, apply the following rules:
- 00:xx — This is midnight. Change 00 to 12 and add AM. (00:00 = 12:00 AM)
- 01:xx to 11:xx — Keep the hour as-is and add AM. (09:30 = 9:30 AM)
- 12:xx — This is noon. Keep 12 and add PM. (12:00 = 12:00 PM)
- 13:xx to 23:xx — Subtract 12 from the hour and add PM. (21:00 = 9:00 PM)
24-Hour Time Conversion Chart
| 12-Hour (AM/PM) | 24-Hour | Note |
|---|---|---|
| 12:00 AM | 00:00 | Midnight |
| 1:00 AM | 01:00 | |
| 2:00 AM | 02:00 | |
| 3:00 AM | 03:00 | |
| 4:00 AM | 04:00 | |
| 5:00 AM | 05:00 | |
| 6:00 AM | 06:00 | |
| 7:00 AM | 07:00 | |
| 8:00 AM | 08:00 | |
| 9:00 AM | 09:00 | |
| 10:00 AM | 10:00 | |
| 11:00 AM | 11:00 | |
| 12:00 PM | 12:00 | Noon |
| 1:00 PM | 13:00 | |
| 2:00 PM | 14:00 | |
| 3:00 PM | 15:00 | |
| 4:00 PM | 16:00 | |
| 5:00 PM | 17:00 | |
| 6:00 PM | 18:00 | |
| 7:00 PM | 19:00 | |
| 8:00 PM | 20:00 | |
| 9:00 PM | 21:00 | |
| 10:00 PM | 22:00 | |
| 11:00 PM | 23:00 |
Military Time
How Military Time Differs
Military time is a specific application of the 24-hour clock used by the armed forces, emergency services, aviation, and healthcare. It is written as a four-digit number without a colon separator and is spoken using the word "hundred." 1400 is spoken as "fourteen hundred hours" and 0930 is "zero nine thirty." Military time eliminates all AM/PM ambiguity, which is critical in operational environments where miscommunication can be dangerous.
Speaking Military Time
Military time is read differently than standard 24-hour time. Each group of four digits is pronounced separately. 0600 is "zero six hundred." 1500 is "fifteen hundred." 2145 is "twenty-one forty-five." Hours before 1000 are prefixed with "zero" — 0800 is "zero eight hundred," not "eight hundred." Minutes are always spoken, not omitted: 0930 is "zero nine thirty," not "zero nine hundred thirty."
Common Time Conversions
What Is 21:00?
21:00 in 24-hour time is 9:00 PM. To convert: 21 − 12 = 9, add PM. Military time: 2100 hours ("twenty-one hundred hours"). This is one of the most searched 24-hour times because 9 PM is a common evening reference point for events, broadcasts, and schedules.
What Is 13:00?
13:00 in 24-hour time is 1:00 PM. To convert: 13 − 12 = 1, add PM. Military time: 1300 hours ("thirteen hundred hours"). The first hour after noon is consistently confusing in 24-hour schedules because 13 looks like a new number, not a continuation of noon.
What Is 00:00?
00:00 is midnight in 24-hour time. It is 12:00 AM in 12-hour format. Military time: 0000 hours ("zero hundred hours"). Some systems use 24:00 to represent the end of a calendar day rather than the start, but 00:00 is the standard and universally accepted representation of midnight.
Frequently Asked Questions
What is 21:00 in 12-hour time?
21:00 in 24-hour time is 9:00 PM. Subtract 12 from the hour: 21 − 12 = 9, then add PM. In military time, this is written as 2100 and spoken as 'twenty-one hundred hours.'
How do you convert PM time to 24-hour format?
For any PM time from 1:00 PM to 11:59 PM, add 12 to the hour. 3:30 PM becomes 15:30. The only exception is 12:00 PM (noon), which stays as 12:00. Drop the PM designation after adding 12.
What is midnight in 24-hour time?
Midnight (12:00 AM) is 00:00 in 24-hour time. This is the start of a new calendar day. In military time it is written 0000 and spoken as 'zero hundred hours.' Noon (12:00 PM) is 12:00, not 00:00.
Is 24:00 the same as 00:00?
24:00 and 00:00 both represent midnight, but they refer to different ends of the same instant. 24:00 marks the end of a day, and 00:00 marks the start of the next. In standard usage, 00:00 is the correct and universally accepted notation for midnight.
What countries use the 24-hour clock?
Most countries outside the United States use the 24-hour clock as the standard. This includes the United Kingdom, all of continental Europe, Canada (officially), Australia, most of Asia, Africa, and Latin America. The United States primarily uses the 12-hour format in everyday life, though the military, aviation, medicine, and transport sectors use 24-hour time.