Military Time Converter (24h ↔ 12h)

Convert between 24-hour ("military") time and the 12-hour AM/PM clock, in either direction. Handles the two cases everyone stumbles on — midnight and noon — correctly.

How to use this calculator

Choose the direction of conversion.
Enter the time — 18:30, 1830 and 6:30 all parse.
For 12-hour input, set AM or PM, then press Convert.

Formula used

PM (except 12) → add 12 · 12 AM → 00 · 12 PM → 12

The full mapping: 1 PM=13:00 … 11 PM=23:00; AM hours pass through except midnight, which becomes 00:00. Midnight and noon are the only genuinely confusing cases — which is why aviation and medicine prefer 24-hour time outright.

Example calculation

Worked example

1830 = 18:30 = 6:30 PM (18 − 12 = 6). Spoken military style: "eighteen thirty hours".

12:00 AM = 00:00 (midnight) and 12:00 PM = 12:00 (noon) — the pair responsible for most missed-appointment stories.

Why 24-hour time exists

The 12-hour clock is ambiguous without AM/PM, and even with it, midnight and noon confuse: "12 AM Tuesday" has scheduled real meetings a full day off. The 24-hour clock removes the ambiguity entirely, which is why hospitals, airlines, militaries, railways and most of the world outside North America use it as standard.

The mental conversion is one subtraction: for afternoon times, subtract 12 (19:00 → 7 PM). Going the other way, add 12 to any PM hour except 12 itself.

Why use this calculator?

Decode flight times, duty rosters and international schedules instantly.
Never mix up midnight and noon again — the tool spells both out.
Learn the add-12/subtract-12 rule through the shown working.

Frequently asked questions

What is 1800 hours in normal time?

6:00 PM. Subtract 12 from any 24-hour value of 13 or higher: 18 − 12 = 6, and since it's past noon, it's PM.

Is midnight 12 AM or 12 PM?

Midnight is 12 AM (00:00 in 24-hour time); noon is 12 PM. Because the labels are so often confused, contracts and airlines usually write 23:59 or 00:01 instead of midnight.

How is military time spoken?

As four digits: 06:30 is "zero six thirty", 18:00 is "eighteen hundred hours", 00:00 is "zero hundred" — no colons, no AM/PM.