FREE Hours to Decimal Calculator

When people refer to “decimal time,” they are often talking about the decimal format of time, which is the more common and practical usage.

This involves expressing traditional time units—such as hours and minutes—as decimal values. For example, 1 hour and 30 minutes is written as 1.5 hours, and 45 minutes as 0.75 hours.

However, it’s important to note that decimal time can also refer to a timekeeping system that was briefly used during the French Revolution.

In this decimal time, the day is divided into 10 hours instead of 24 hours.

An hour is made up of 100 minutes, and one minute is made up of 100 seconds. This technically means that there are 100,000 seconds in a day.

While decimal time was briefly used in real life during the French Revolution, today it’s mostly a theoretical concept.

However, a decimal format is still used in fields like payroll or data analysis because it makes it easier to multiply or divide time.

Generally, we convert time to decimal in order to simplify calculations, especially for payroll.

Employees track their hours in hours and minutes but their pay rates are expressed using the decimal system. Because of this, work time has to be converted into its number form (decimal) in order to calculate work hours and process payroll.

Example:

To calculate the pay of someone who worked 7 hours and 30 minutes in a day, one must:

1. Convert worked time into decimals
2. Multiply the decimal format by the hourly wage

So, for someone working 7 hours and 30 minutes, the 30 minutes would need to be converted into a decimal (which would be 0.5).

If the hourly rate is $15, the total owed wage would be:

• 7.5 (decimal time) × $15 (hourly rate) = $112.50 (total pay due)

Without the conversion, the rate would be incorrect as below:

• 7:30 (standard time format) x $15 (hourly rate) = $109.50 (incorrect total pay due)

Decimal time was invented during the French Revolution as part of a broader effort to create a rational, secular alternative to the traditional systems that were tied to religion and monarchy.

Key figures behind the idea included astronomer Joseph Jérôme Lalande and Gilbert Romme, a mathematician and politician who supported the new system.

Although the system was officially adopted in France in 1795, it was ultimately abolished in 1806 by Napoleon Bonaparte, who sought to restore traditional timekeeping to align more closely with the Church and gain political support.

To convert time to decimal hours, minutes must be divided by 60 to get the fraction of an hour.

The total is then added to the total number of hours.

This results in time expressed in decimal format.

Practical Example: Let’ s convert 5 hours and 45 minutes to decimal hours:

• First: Divide the minutes by 60: 45 minutes ÷ 60 = 0.75

• Second: Add the result to the hours: 5 hours + 0.75 = 5.75

The result is the decimal time: 5.75.