Its Decimal Hours VS Hours:Minutes

We talk with customers everyday who are confused about decimal hours(e.g. 4.25)and hours/minutes (e.g. 4:15).  Here we go into the math on performing the decimal to hours/minutes conversion and the reasons why you one would want to do the conversion at all.

Kind of a big thing if you work with employee hours for payroll!

Spoiler

There is an awsome hours converter link at the bottom of this page, or just click here

The big thing to look for is a decimal point(.) or colon(:)

So our time cards page displays employee hours in the decimal hours format. Decimal hours can sometimes cause a bit of confusion for people who are used to looking at hours in the hh:mm format.  Here are a few examples of decimal hours and how to interpret them…

• 8.00 hours - this is exactly 8 hours OR 8:00 in the hh:mm format - note colon, not a decimal point
• 8.25 hours - this is 8 and 1/4 hours, or 8 hours and 15 minutes OR 8:15 (hh:mm again), again note the colon
• 8.50 hours - here we have 8 and ½ hours or 8 hours and 30 minutes. OR 8:30
• 8.75 hours - 8 hours and 45 minutes OR 8:45

Here are a few which are commonly confused.

• 8.20 hours - you may want to read this as 8 hours and 20 minutes, but notice the decimal point, it is actually 8 hours and 12 minutes
• 8.45 hours - this one is 8 hours and 27 minutes

Why use decimal hours? We use decimal hours for two reasons…

They are more precise - decimal hours are almost 2 times more precise than minute hours.  Minute hours have a maximum of 1/60 resolution, while decimal hours have a 1/100 resolution. Kinda technical, sorry.
Decimal hours are easier to work with - Imagine trying to multiply 8:12 (which is 8 hours and 12 minutes) by an employee hourly rate.  It’s much easier to multiply 8.20(or 8 hours and 12 minutes)  by an hourly rate to calculate payroll.

A Bit Of Time Clock History

While we could not find  a lot of data on why the hh:mm format lasted so long we do have a few ideas…

• The very first time clocks were people.  A person would simply write down when an employee got to work and when they went left work.  What would they write down?  Times such as 8:00am and 5:00pm. To calculate worked time, a payroll person would figure hours and minutes worked, but would then convert to decimal hours to do the multiplication.
• The next time clocks were the old school wall mounted punch clocks.  An employee would insert their punch card and what would be “punched” on it, again a time in the hh:mm format. And again a payroll person would convert to decimal hours.
• So what came next, computer based punching.  The early computer systems simply mimicked their predecessors.  The hh:mm addition persisted, and at the very end the hh:mm format would be converted to decimal hours for payroll.

So why the big ole hairy article?  

We wanted to tell you that we built a nice converter for you, here it is...

Minutes To Hours Calculator