24 Hour Clock Converter

There are simply two main methods of displaying time. The 12 hour clock uses AM and PM, then the 24 hour clock. Let's find the differences between both of them, and how to calculate or convert them.

12-Hour Clock

The day is divided into two 12-hour periods: 

• midnight to noon (AM hours), and 
• noon to midnight (PM hours).

The acronyms AM and PM come from Latin:

• AM: ante meridiem (before midday) 
• PM: post meridiem (after midday)

24-Hour Clock

The day spans from midnight to midnight and is divided into 24 hours, numbered from 0 to 23. Time is displayed in hours and minutes since midnight.

Changing 12-Hour Time to 24-Hour Time

• Use 00:00 to signify midnight in a 24-hour time.
• Eliminate “AM” for the hours between 1:00 and 11:59 AM.
• Leave the noon hour as-is, but remove "PM."
• Add 12 to the hours between 1:00 and 11:59 PM and eliminate "PM.

Remember, a picture is worth a thousand words. Use the conversion image provided as a visual guide to familiarize yourself with the 12 vs. 24-hour time concept. This tool will support your learning and help you master the conversion process.

Converting AM/PM to 24-hour clock

• 12:30 AM = 0:30
• 11:50 AM = 11:50
• 3 PM = 15:00
• 4 PM = 16:00
• 4:23 PM = 16:23
• 5 PM = 17:00
• 11:51 PM = 23:51

Converting 24 hour clock to AM/PM

• 0:15 = 12:15 AM
• 2:22 = 2:22 AM
• 12:30 = 12:30 PM
• 14:07 = 2:07 PM
• 23:47=11:47 PM
• 23:59=11:59 PM

24 Time Conversion Chart

The 24-hour time system is similar to standard AM/PM time, with the exception that you continue counting up after 12 PM (noon). So, in 24-hour format, 1 PM equals 13:00, 2 PM equals 14:00, etc. To convert to 24-hour format, simply add 12 to any PM time.

Here is a side-by-side comparison of the 24-Hour Clock and a Standard 12-hour AM/PM:

In case you want to download a time conversion chart, we do provide a PDF version free of charge.

Note: "12 AM" and "12 PM" can cause confusion, so we prefer "12 Midnight" and "12 Noon".

24-hour clock – where is it used?

The 24-hour time clock system is the most used in the world, especially in Europe and is the international standard notation of time. (ISO 8601).

In the United States, Great Britain, Ireland, Canada, Australia, and New Zealand, the 12-hour AM/PM format is still more commonly used. In these countries, the 24-hour format is sometimes referred to as 'Military time'.

Should "AM" be "ante meridiem" or "ante meridian" (likewise for PM)?

The official (according to an American, Australian, and British dictionary) and most common spelling for AM is "ante meridiem," a Latin phrase.

But people sometimes use the phrase "ante meridian" (a "meridian" in this case refers to an imaginary line in the sky when the sun is at its highest point).

Learn about AM PM full form.

The 24-hour time format is usually used in transportation, medical, and military industries to avoid confusion. The 24-hour clock is also called railway/railroad time, military time, and continental time.

In case you need to make more complex calculations, use our hours calculator.

How to use the 24 hour format effectively?

You might be looking for such 12 to 24 hour conversion because you might want to schedule a call with someone from a different part of the world. And this calculator will help. Yet, there are some additional aspects that you need to consider aside of the time format.

• Timezone differences. If you're in New York (Eastern Time) and want to speak with someone from Paris (Central European Time), note that Paris is 6 hours ahead NY.
• Daylight Saving Time (DST). Many countries adjust their clocks. These clock adjustments are conducted in the spring and fall, often between mid-to-late March and late-October to early November. Because certain marketing content is seasonal, keep in mind that in the Northern Hemisphere, spring begins in March, while in the Southern Hemisphere, March begins fall.
• Date formats. Between countries, time formats can change. For example, in US, we're used with MM-DD-YYYY, while in Europe the common format is DD-MM-YYYY, where MM - month, DD - day, YYYY - year.
• Holidays. The further you go, the more diverse the country traditions, cultural norms, religion and holidays. So, before scheduling your call, make sure to check the national holidays of your target audience's locales.