Whether you want to know the equivalent of time expressed in hh:mm:ss in its decimal form, or do some math, such as adding or subtracting hours, minutes, or seconds – you will eagerly look for a tool like our Time to Decimal Calculator. It is a very handy and easy-to-use tool that instantly converts any time into its decimal equivalent.

Would you like to explore more of our calculators related to time, times zones, drive times or times conversions? Take a look at the list below of some calculators we recommend you to check out:

Decimal Time

What does decimal time represent? 

It represents the time of day using decimal units. It often refers to the system of time, which was most popular in France in 1792 during the French Revolution. 

The system at that period worked by dividing the day into 10 decimal hours. In addition, each decimal hour consisted of 100 decimal minutes and each minute was made of 100 decimal seconds. Therefore, one day was equivalent to 100000 decimal seconds.

In opposition, a standard UTC works by dividing the day into 24 hours. Each hour equals 60 minutes, and each minute is made of 60 seconds. Therefore, one day in UTC standard format is equal to 86400 seconds.

Considering which time system is simpler and easier for conversion and calculations, the winner is a decimal format system. Why? Because it’s easier to interpret it and perform conversions if the time is expressed in decimals. 

For instance, let’s assume you want to interpret 1:25:30 (hh:mm:ss) as a time in decimal form. How would it look in a decimal format?


  • 1.2530 – hours
  • 125.30 – minutes
  • 12530 – seconds

Or, for example, when you want to convert 3 hours in minutes and seconds. Again, it is straightforward: 3 hrs = 300 minutes or 30,000 seconds. 


When did it all start, and at what period in history decimal time system was used?

In the 1790s in France, after the introduction of metric weights and measures, people divided a day into 10 hours, where each hour equalled 100 minutes and each minute was equivalent to 100 seconds. However, it’s important to mention that the old time system failed to become popular and spread its usage worldwide.

In 1795 when a standardised system was introduced, which was way more useful and effective, these localised weights and measures, decimals system pretty much was already dead.

Today, standardised systems are used everywhere, including time. Therefore, there are zero chances that the decimal system may come into use and become a part of everyday life.

Decimal vs Standard 24-hour System

We learned about the decimal time system and its origins, but what about the 24-hour time system? What are its origins?

Interestingly, Egyptians were the first people who used a 24-hour system, and they divided a day into 24 equal parts. They used a sexagesimal system, with a base of 60, which was afterwards accepted and used by Babylonians.

Additionally, Babylonians divided both the circle and the year into 360 segments. Our todays’ way of measuring and expressing time originates from the old Egyptian time.

What does 24-hour standard time look like?

In the 24-hour system, we express hours as 60 minutes and minute as 60 seconds. For instance, there are 1,440 minutes in a day, and 1 hour in seconds is equal to 3600. Whenever you see this format “hh:mm” or extended “hh:mm:ss”, it indicates that the time is expressed in the standard 24-hour time system.

Example: 4:10:15 – we read as “four hours, ten minutes and fifteen seconds”. Additionally, it means that there are four periods of 60 minutes, one period of 10 minutes and 10 seconds.

What does a decimal time look like?

The decimal time system uses base 10 to express time. Therefore, each place in a decimal number ranges from 0 and 9.

Example: If we use the same example from above (4:10:15), how can we write it as a decimal time?

We express it as 4 hrs – 250 min – 15,015 sec in decimal format.

How to Convert Time to Decimal – Formula

There are cases when you need to express your time in decimals, converting time to decimal hours, minutes and seconds. Therefore, you can see all three formulas required for converting time to decimals below.


Sometimes you need to express time in decimal hours. Therefore this is the formula you should utilize:

Hours = hh + (mm \div 60) + (ss \div 3600)


  • hh – hours component of the time
  • mm – minutes component of the time
  • ss – seconds component of the time

For instance, converting 3:05:00 to decimal hours:

Hours = 3 + (10 \div 60) + (0 \div 3,600)

Hours = 3 + 0.16 + 0 = 3.16


If you want to convert it to decimal minutes only, choose this formula instead:

Minutes = (hh \times 60) + mm + (ss \div 60)

For example, converting 3:05:00 to decimal minutes:

Minutes = (3 \times 60) + 5 + (0 \div 60)

Minutes = 180 + 5 + 0 = 185


For converting it to decimal seconds, check out the formula below:

Seconds = (hh \times 3600) + (mm \times 60) + ss

For example, converting 3:05:00 to decimal seconds:

Seconds = (3 \times 3,600) + (5 \times 60) + 0

Seconds = 10,800 + 300 + 0 = 11,100

Time Conversion Chart

Here is the decimal chart (table) of the most common time expressed in decimal hours, minutes, and seconds. Instead of calculating it manually or using calculators, you can take the calculated values from the chart below.

05:00:00 530018,000
06:00:00 636021,600
08:00:00 848028,800
The most common times expressed in decimal hours, minutes, and seconds.

Time to Decimal Calculator – How to Use?

We’ve come to the most interesting part. If you are in a hurry or just lazy and not up to doing math calculations, we have developed a special calculator (converter). Our converter efficiently listens to your input (in hh:mm:ss format) and instantly converts it to decimal hours, minutes and seconds.

Note: An extra feature you can enable in the calculator is the “step-by-step solution” mode which, besides returning the result, displays a step-by-step process of conversion using all three formulas you saw in the previous sections.

How to utilize our calculator?

  • Enter the parameters in the calculator (hours, minutes and seconds)
  • The calculator calculate the total time and displays it in decimal hours, minutes and seconds
  • Additionally, go through a step-by-step explanation of the conversion by setting “see step-by-step solutions” to “Yes”

Time to Decimal Calculator – Example

Okay, let’s take an imaginary time and use our calculator to turn it to a decimal. We will enable the “step-by-step solutions” option, as well.

Scenario: Convert 03:22:15 (hh:mm:ss) to decimal hours, minutes and seconds using the calculator.

  1. Enter each value to a defined parameter field in the calculator (03 to hours, 22 to minutes and 15 to seconds)
  2. Time to Decimal Calculator uses all three formulas to calculate and convert your time to a decimal. Therefore, in our case, it returns: 

    Hours: 3.371 
    Minutes: 202.25
    Seconds: 12,135


What is 1 hour and 30 minutes as a decimal?

1 hour and 30 minutes written as a decimal equals 1.5
hours, 90 minutes and 5400 seconds.

How do you convert time into decimals?

You can convert time into decimals using one of the following formulas:
Hours = hh + (mm \div 60) + (ss \div 3600)
Minutes = (hh \times 60) + mm + (ss \div 60)
Seconds = (hh \times 3600) + (mm \times 60) + ss

How to convert 30 minutes to hours?

Converting 30 minutes to decimal hours equals 0.5 hrs.

How to write 1:20:50 as a decimal?

It is equivalent to:
– 1.3472 hours
– 80.83 minutes
– and 4,850 seconds

How to convert 45 minutes to decimal minutes?

You can convert 45 minutes to decimal minutes by using the formula below:
Minutes = (hh \times 60) + mm + (ss \div 60)

So, you need to:
– multiply the number of hours by 60
– add the number of minutes to the product of the previous calculation
– divide the number of seconds by 60 and add the product to the sum

How to convert 3:32:10 to decimal?

It is equivalent to:
– 3.536 hours
– 212.17 minutes
– and 12,730 seconds