24-Hour to 12-Hour Time Converter
Written by Thierno Sadou Diallo, formula verified per our methodology • Last checked on 9/5/2026
To convert a time from 24-hour to 12-hour format, subtract 12 from hours after noon (13:00 becomes 1:00) and add AM before noon, PM from noon onward. So 14:30 becomes 2:30 PM.
Explanation
Many countries use the 24-hour format (0:00 to 23:59) in daily life, while the United States, English-speaking Canada, and many systems or software of American origin use the 12-hour format, with AM (ante meridiem, before noon) and PM (post meridiem, after noon). The conversion follows a simple rule: between 1:00 and 12:00, the hour stays the same and AM is added (except midnight, a special case below); between 13:00 and 23:00, 12 is subtracted from the hour and PM is added. Two edge cases deserve special attention, as they're the most common source of errors in this conversion: midnight (0:00) becomes 12 AM, not 0 AM as one might intuitively think; noon (12:00) becomes 12 PM, not 12 AM. This conversion is useful for understanding a time shown on a device or software set to English, for booking a flight or hotel on a US website, or for communicating a schedule to someone used to the 12-hour format. To calculate a time difference or plan a meeting across time zones, see also our day of the week calculator or our date difference calculator.
Example: converting 14:30
Inputs
Hour: 14. Minutes: 30.
Calculation
14:00 is after noon, so 12 is subtracted: 14 − 12 = 2, with the PM label. The minutes (30) stay unchanged.
Result
14:30 corresponds to 2:30 PM in 12-hour format.
Frequently asked questions
Why does midnight become 12 AM and not 0 AM?
The 12-hour format has no digit 0: hours are numbered from 1 to 12 only. Midnight marks the start of the AM period, so it's conventionally labeled 12 AM rather than 0 AM, even though this can seem counterintuitive at first.
And why is noon 12 PM and not 12 AM?
Noon marks the start of the PM period (after noon), not the end of the AM period: that's why it's labeled 12 PM. It's the mirror image of midnight, which marks the start of the AM period and is therefore labeled 12 AM, not 12 PM.
Can this calculator also convert from 12-hour to 24-hour format?
This calculator only converts from 24-hour to 12-hour format. For the reverse conversion, the rule is symmetric: an AM hour keeps its value (except 12 AM, which becomes 0:00), and a PM hour adds 12 (except 12 PM, which stays 12:00).