Decimal Time Calculator

Use the simple zistemo time converter to calculate decimal time to hours and minutes and vice versa.

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Convert time to decimal hours

Converting time values is a crucial skill in many fields. There are various types of time units. It is essential to convert them correctly in order to obtain accurate results because mostly it is employee time recorded by a time clock that needs to be calculated.

Time is an abstract concept that describes the progression of events. It can be measured using various units such as microseconds, milliseconds, seconds, minutes, hours, days, weeks, months and years. The ability to convert these units is essential to accurately represent and compare time in different contexts.

There are several formats for displaying hours and minutes


12-hour format

This format is widely used in the United States and Canada. To show a difference between morning and evening the 12-hour format is using AM and PM. AM means Ante meridiem and indicates the time is before noon while PM stands for Post meridiem and shows that a time is after noon. Most digital clocks showing midnight as 12:00 AM and noon as 12:00 PM.


24-hour Format

The 24-hour time format, also known as military time, represents hours within a range from 0 to 23, without any distinction between morning and evening. For instance, 14:30 is represented as 14:30. This format is commonly used in scientific, medical, and military contexts, as well as in many parts of Europe, Africa, Asia and the Middle East.


Decimal Time

For example, 12:30:15 is represented as 12.5025. One hour is equal to 1.0, one decimal minute is equal to 1/60, and one second is equal to 1/3600. Decimal time is convenient for mathematical calculations, but often needs to be converted back to hours and minutes for everyday usage. Decimal time format is also used to compare time durations in a decimal number.

Table of minutes and decimal time

The following table lists the minutes in the time format with the respective decimal values as a conversion chart.

Minutes Decimal
00:01 0.017
00:02 0.033
00:03 0.050
00:04 0.067
00:05 0.083
00:06 0.100
00:07 0.117
00:08 0.133
00:09 0.150
00:10 0.167
00:11 0.183
00:12 0.200
00:13 0.217
00:14 0.233
00:15 0.250
00:16 0.267
00:17 0.283
00:18 0.300
00:19 0.317
00:20 0.333
00:21 0.350
00:22 0.367
00:23 0.383
00:24 0.400
00:25 0.417
00:26 0.433
00:27 0.450
00:28 0.467
00:29 0.483
00:30 0.500
00:31 0.517
00:32 0.533
00:33 0.550
00:34 0.567
00:35 0.583
00:36 0.600
00:37 0.617
00:38 0.633
00:39 0.650
00:40 0.667
00:41 0.683
00:42 0.700
00:43 0.717
00:44 0.733
00:45 0.750
00:46 0.767
00:47 0.783
00:48 0.800
00:49 0.817
00:50 0.833
00:51 0.850
00:52 0.867
00:53 0.883
00:54 0.900
00:55 0.917
00:56 0.933
00:57 0.950
00:58 0.967
00:59 0.983
01:00 1.000

Decimal time is primarily used in fields that require precise timekeeping, such as science, technology, mathematics and engineering. However, it is important to note that decimal time is not widely used in everyday life and is less common compared to the traditional 12-hour or 24-hour clock formats.

Time Conversion Factors

Of course, there are many units and formats for times, but the ones mentioned above are the most common. Let's consider how does the time conversion work specifically to convert decimal hours to other time formats with hours minutes and seconds.

How do I calculate decimal time?

Converting hours and minutes into a decimal number is not complicated and almost no calculator is needed. The time zone doesn't matter because the decimal system always represents a duration and not a specific point in time. The formula for this is:

Number of minutes/60 = Conversion of hours and minutes to decimal

Converting a small unit of time into a larger unit

In general, when converting from a smaller unit of time to a larger one, division is necessary. To convert from seconds to minutes, the number of seconds is divided by 60. Similarly, to convert minutes to hours, the number of minutes is divided by 60. The result is a decimal number and can be easily converted to the 24-hour format. For example:

30 seconds = 30/60 = 0.5 minutes

55 minutes = 55/60 = 0.917 hours

When converting hours to days, the process is different. The number of hours must be divided by 24 as there are 24 hours in a day.

12 hours = 12/24 = 0.5 days

Converting a large unit of time into a smaller unit

To convert a large unit of time into a smaller unit, the conversion factor must be multiplied. For example, to convert hours to minutes, the number of hours is multiplied by 60.

4 hours = 4x60 = 240 minutes

Development of the 24-hour time format

The system of dividing a day into 24 equal hours, each hour into 60 minutes, and each minute into 60 seconds, has its roots in ancient civilizations of Egypt and Greece. Throughout history, this system has been refined and developed further. In its earliest forms, the day was divided into 12 hours which were used to measure both daytime and nighttime. Later, these 12 hours were divided into smaller units of time. The ancient Romans advanced this concept by basing it on the position of the sun, allocating 12 hours for daylight and 12 hours for nighttime.

As clock-making technology advanced during the Middle Ages, more precise clocks were created, resulting in more accurate timekeeping. The invention of pendulum clocks in the 17th century, followed by the development of spring-driven and quartz clocks, greatly improved the precision of measuring time units.

The origin of the decimal system

The decimal system is a number system that utilizes 10 digits, from 0 to 9. The reason for its creation is likely due to the fact that humans have ten fingers which made it more convenient for them to work with a number system based on 10. Some scholars argue that it was used by ancient cultures in different parts of the world, while others suggest that it was developed more recently.

A decimal number of hours allows time to be expressed as a fraction of a day, enabling mathematical comparison, data analysis and calculations with other numerical values. For example, calculating the duration between two specific points in time in hours or minutes. Representing time in decimal format simplifies the process of calculating the difference between values and eliminates the need to convert them into hours and minutes. Additionally, the decimal format is more convenient to present and analyze time data in tables, charts and graphs.

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The 12-hour or 24-hour format is the most commonly used in daily life, as it provides a clear and convenient way to express a specific time. To perform mathematical calculations with time, it is recommended to use decimal hours, which requires converting units. The process of converting time is not uncommon and similar to converting other units of measurement such as weight or length. There are various online calculators available, such as the one on this page for converting minutes to decimal time, which can assist with the conversion process. Often they are referred as a duration calculator or hours calculator. The key to achieving a successful conversion is using the correct conversion factors and having a thorough understanding of the units being converted.

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