Military Time Converter – 24-Hour Clock
Convert 12-hour clock time to military (24-hour) time and back, or find the difference between two military times. Enter the hour, minutes and AM/PM, or a four-digit time such as 1430.
Convert 12-Hour and Military Time in Both Directions
Military Time Formula
Where:
- \(h_{12}\) — hour on the 12-hour clock (1 to 12)
- \(h_{24}\) — hour on the 24-hour clock (0 to 23)
- \(m\) — minutes (0 to 59)
- \(t_{\text{mil}}\) — the four-digit military time, e.g. 1430
The same expression handles the two midnight cases automatically: 12 AM gives \(12 \bmod 12 = 0\), and 12 PM stays 12 because 12 + 12 is reduced modulo 24 only when needed.
To convert in the other direction, take \(h_{12} = h_{24} \bmod 12\) (replacing a result of 0 with 12) and label hours below 12 as AM, hours from 12 upward as PM.
Military Time – Calculation Example
Example: converting 2:30 PM to military time. The hour is 2, the minutes are 30, and the period is PM.
\[ h_{24} = (2 \bmod 12) + 12 = 14 \qquad t_{\text{mil}} = 100 \cdot 14 + 30 = 1430 \]
Result: 2:30 PM = 1430 (or 14:30), spoken as "fourteen thirty hours".
Second example (difference mode): a shift runs from 0830 to 1730.
\[ 8 \cdot 60 + 30 = 510 \text{ min}, \quad 17 \cdot 60 + 30 = 1050 \text{ min}, \quad 1050 - 510 = 540 \text{ min} = 9 \text{ h } 0 \text{ min} \]
Result: the difference is 9 hours 0 minutes.
How to use the calculator
- Pick a Conversion Mode: 12-hour → military time, military → 12-hour time, or the difference between two military times.
- For a 12-hour to military conversion, enter the Hour (1–12), the Minutes (0–59) and select AM or PM.
- For a military to 12-hour conversion, type the Military Time as four digits (1430) or with a colon (14:30). Values from 0000 to 2359 are accepted, plus 2400 for the very end of the day.
- For a difference, fill in the First Military Time and the Second Military Time. If the second time is earlier than the first, the calculator assumes the interval crosses midnight.
- Read the result: it shows the converted time in 4-digit and colon format, how it is spoken aloud, and a short explanation of the rule that was applied. The result block also includes a live 24-hour chart of your current local time and a full conversion chart for all 24 hours.
What military time is
Military time is the everyday name for the 24-hour clock: the hours run from 00 (midnight) to 23 (11 PM) without an AM/PM suffix, and the minutes follow directly after the hour. The time 1430 therefore means "14 hours and 30 minutes since midnight", which is 2:30 PM on the 12-hour clock. Because every moment of the day has one unambiguous number, there is no confusion between 2:30 in the afternoon and 2:30 in the small hours of the morning.
That is precisely why the format is standard in aviation, hospitals, emergency services, logistics and the armed forces — anywhere a misheard "two-thirty" could have real consequences. Written as four digits, a time is short to say and hard to mistake, which is also why flight schedules, train timetables and medical charts often use it.
Two special moments deserve attention. Midnight is written 0000 (the start of the day) or sometimes 2400 (the end of the day); they refer to the same instant, but 2400 is reserved for closing out a day, e.g. a shift that ends at midnight. Noon is 1200. Slightly confusingly for beginners, 12 AM is 0000 while 12 PM is 1200 — the calculator's "Details and Rules" line spells out which case applies to your input.
Spoken military time adds the word "hours" and reads single-digit minutes with a leading zero: 0800 is "zero eight hundred hours", 1430 is "fourteen thirty hours", and 0905 is "zero nine zero five hours". The calculator shows this spoken form for your entry and includes a small table of how the minutes are pronounced.
Limitations and tips
- The calculator works with clock time only — it does not handle dates or time zones. If you need to add or subtract durations across days, use the Time Calculator or the Time Duration Calculator instead.
- The difference mode always assumes the interval is at most 24 hours: if the second time is earlier in the day than the first, the span is treated as crossing midnight. Two identical times give a difference of 0, not 24 hours.
- Minutes above 59 or hours above 23 are rejected; the only four-digit value beyond 2359 that is accepted is 2400, and only with 00 minutes, as it marks the end of a day.
- Leading zeros matter in military time: 0830 is a valid eight-thirty, while 830 typed without the zero will not parse as four digits — if in doubt, use the colon form 8:30 or 08:30.
- When converting for timesheets, remember that payroll often wants decimal hours rather than hours and minutes; the Hours to Decimal Converter handles that step.
- For planning when you will arrive somewhere after adding a travel duration to a departure time, the Road Trip Arrival Time Calculator is the better tool.
Frequently Asked Questions
How do I convert military time to regular time in my head?
For hours 13 to 23, just subtract 12 and add PM: 1730 becomes 5:30 PM, 2315 becomes 11:15 PM. Hours 01 to 11 keep their number as AM (0900 is 9:00 AM). The two tricky cases are 0000 = 12:00 AM (midnight) and 1200 = 12:00 PM (noon). With a colon format like 14:30 there is nothing else to do — only the hour changes, minutes stay the same.
Is midnight 2400 or 0000?
Both refer to the same moment, but they belong to different days. 0000 marks the start of a new day, while 2400 marks the very end of the day that is closing. That is why a night shift might be written 2200–2400 (ends at midnight) while the next shift starts at 0000. In everyday use, 0000 is far more common; the calculator accepts 2400 only with 00 minutes.
Why is 12 AM midnight and 12 PM noon? It seems backwards.
In the 12-hour system, the 12 belongs to the half-day that is just ending, not the one starting. So 12 AM is the last hour of the night (midnight), and 12 PM is the last hour of the morning (noon). Military time avoids this trap entirely: noon is 1200 and midnight is 0000, which is one reason hospitals and airlines prefer it.
How do I calculate the time difference between two military times without a calculator?
Convert each time to minutes since midnight: multiply the hour by 60 and add the minutes. Then subtract the smaller from the larger and convert the result back to hours and minutes. From 0830 to 1730: \(8 \times 60 + 30 = 510\), \(17 \times 60 + 30 = 1050\), \(1050 - 510 = 540\) minutes = 9 hours. If the end time is earlier, add 1440 to account for crossing midnight.
How do I say military time out loud?
Add the word "hours" at the end. Exact hours use "hundred": 0800 is "zero eight hundred hours", 1200 is "twelve hundred hours". Otherwise read the minutes too: 1430 is "fourteen thirty hours". Single-digit minutes are spelled out one by one with a leading "zero": 0905 is "zero nine zero five hours". Only hours below 10 need the initial "zero".
Is military time the same as the 24-hour clock used in other countries?
Yes, mathematically they are identical — "military time" is just the American name for the 24-hour clock, which is the everyday standard in Europe and much of the world. The difference is notation: written military time drops the colon (1430 instead of 14:30) and always uses four digits, while most civilian 24-hour notation keeps the colon. The times themselves convert exactly the same way.
Do I need to write the leading zero in military time?
Yes, if you use the four-digit format. 0830 is a valid eight-thirty, but 830 typed without the zero is only three digits and will not parse — the hour and minutes split becomes ambiguous. If you cannot type the leading zero, write the time with a colon instead: 8:30 or 08:30 are both accepted and unambiguous.