How To Convert Decimal Hours To Hours And Minutes

Its Decimal Hours VS Hours:Minutes

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


There is an awsome hours converter link at the bottom of this page.

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...