Category: Philips

How They Calculate Your CFL’s Savings

If you’ve ever tried to figure out how the savings using CFL’s vs. old school incandescents are calculated and if they’re actually accurate, I understand your confusion.
The manufacturers of the energy-efficient compact fluorescents we sell here at Adventure Lighting make what we believe are the highest quality CFL’S on the market. But they don’t always do the best job of explaining how they come up with how this CFL saves this many watts at this many lumens over this many hours at this cost per hour.
I’m certainly no math wizard – but there is a method to their madness.
Take a typical Philips 18w compact fluorescent – it produces a light output of 1250 lumens of light, lasts 12,000 hours (or about 11 years) and saves $68 dollars in energy costs compared to a comparable old school incandescent – according to Philips. 

But how do we know they’re right? We know they’re right because we know the U.S. Federal Government is right. (Okay, insert your joke here lol)   

The Environmental Protection Agency rates all lights under strictly controlled test conditions, typically with lamps turned off and restarted about once every three hours.  There are 100 lamps tested, and when half of them have failed, the rated average life of a light is determined.  For this lamp, half of all the tested lamps have failed at the 12,000 hour mark.      

At $.10 per kilowatt-hour (the average cost of electricity across the US) the 18w CFL we’re referencing uses $21.60 of electricity over its 12,000 hour life. This is a $68.40 in savings compared to the $90 cost of using a 75w old school incandescent bulb.    

In simpler terms, CFL’s last from eight to 15 times longer yet use only 20 to 33% of the energy of incandescents – and those are numbers that don’t require a math degree to understand.  Another quality of CFL’s is that the more you turn them on and off the shorter their life expectancy – conversely, the longer you let them burn the longer the life.    

To calculate how much you can save replacing multiple incandescents with CFL’s, go to our website, and click “calculate your savings.”    

But if you really want to understand firsthand how CFL’s work, the easiest thing to do is use one – and we can help!    

Just subscribe to our blog via the email subscription area on the right hand side of this page and we’ll give you two free Philips CFL’s. (while supplies last) We’ll send you a confirmation email and how to pick up your two free lights after you subscribe. No purchase necessary.    

And keep an eye out for more great offers in future blogs!    


Jack Huff, along with his son Brian and wife Sue, owns and manages Adventure Lighting in Des Moines, Iowa. For more information, go to     

Back to the top