Military Time Converter Calculator
Convert between 12-hour and 24-hour time instantly. Type in either box and the other updates automatically.
What Is Military Time?
Military time, also called the 24-hour clock, is a way of telling time where the day runs from 00:00 (midnight) to 23:59 (one minute before midnight the next day). It never resets at noon like the 12-hour clock does. Instead, it just keeps counting up.
It is used by the military, emergency services, hospitals, airlines, meteorologists, and in most countries around the world. In the United States, it is often called military time, but elsewhere it is simply the standard way of reading a clock.
The system is famously simple. Once you see the pattern, converting between 12-hour and 24-hour time becomes second nature.
How Military Time Works
The day is divided into 24 hours. The first 12 hours (midnight to just before noon) are labeled 00 through 11. The next 12 hours (noon through just before midnight) are labeled 12 through 23. Here is how the full day looks:
The blue half covers AM hours. The orange half covers PM hours. The 5th marker, right where the colors meet, is noon (12 PM / 12:00).
How to Convert in Seconds
The only rule you really need: in the PM, add 12 to the hour or count the hours after 12 PM (e.g. 1 PM is 1 hour after 12 PM, it becomes 13:00. 2 PM is 14, 3 PM is 15, etc.). In the AM, just drop the AM. Two special cases handle the tricky edges: 12 AM becomes 00, and 12 PM stays as 12.
Here is the full PM conversion pattern. Every PM hour between 1 and 11 follows the exact same rule:
Going the other direction is just as easy. If the 24-hour time is 13 or higher, subtract 12 and add PM. If it is 00, that is 12 AM. If it is between 01 and 11, it stays the same and you add AM. If it is 12, that is 12 PM (noon).
Quick Reference Table
These are the times people get stuck on the most. Once you memorize these, the rest is obvious:
| 12-Hour | 24-Hour |
|---|---|
| 12:00 AM (midnight) | 00:00 |
| 1:00 AM | 01:00 |
| 2:00 AM | 02:00 |
| 6:00 AM | 06:00 |
| 11:00 AM | 11:00 |
| 12:00 PM (noon) | 12:00 |
| 1:00 PM | 13:00 |
| 2:00 PM | 14:00 |
| 6:00 PM | 18:00 |
| 9:00 PM | 21:00 |
| 11:00 PM | 23:00 |
| 11:59 PM | 23:59 |
Why Is It Called Military Time?
Military time is the common U.S. term for using a 24-hour clock instead of separating the day into AM and PM. The system makes it easier to communicate exact times and avoid confusion, especially in situations where a misunderstanding could cause problems. "Meet at 7" is dangerously vague. "Meet at 19:00" is not.
The U.S. Navy began using the 24-hour system around 1920, and the U.S. Army officially adopted it in 1942 during World War II. The military's use of the system helped establish the term "military time" in the United States.
Because it removes AM and PM entirely, military time cannot be misread. There is no confusion between 7 in the morning and 7 at night. That clarity is why hospitals, air traffic control, and emergency services all rely on it.
Frequently Asked Questions
How do I say military time out loud?
Read the numbers as they appear. 15:30 is "fifteen thirty." 08:00 is "oh eight hundred." 00:00 is "zero hundred" or "midnight." Hours are often followed by the word "hours," like "fifteen hundred hours."
Is 12 AM midnight or noon?
12 AM is midnight and 12 PM is noon. This is a common point of confusion in the 12-hour system. In military time there is no ambiguity: midnight is 00:00 and noon is 12:00.
Should midnight be 00:00 or 24:00?
Both are used depending on context. 00:00 marks the start of a new day, while 24:00 sometimes marks the end of the previous day. This tool uses 00:00, which is the more common convention.
Why does military time start at 00 instead of 1?
Because the day has 24 hours, they are numbered 0 through 23 rather than 1 through 24. Starting at zero makes the math cleaner and matches how clocks work in computing and science.
Do other countries use military time?
Yes. Most countries outside the United States use the 24-hour clock as their standard way of telling time. In those places, it is not called military time, it is just the clock.
What is the quickest way to learn military time / the 24 hour format?
Add 12 to any hour after 12:00 PM, or count the hours after 12:00 PM. 2:00 PM + 12 = 14:00. 15:00 is 3 hours after 12, it is the equivalent to 3:00 PM. You can try going into your phone's settings and changing the clock format to force yourself to learn quicker!