LED Lights – The Basics

Let’s demystify all the technical jargon you see on the back of an LED bulb package. I’m going to cover everything you’ll find on an LED light label and give you my tips on choosing the right bulb.

What Are Lumens?

Let’s start with light output. On an LED light package you’ll see something called lumens. This is the amount of light or how bright a bulb will be. You don’t need to understand the science behind measuring lumens. You just need to know that the higher the number the more output you’ll get from a bulb. So when two different bulbs say they are equivalent to a 60w bulb, you can use this number to determine which one is brighter. If the packaging only includes lumens and doesn’t include an equivalent incandescent wattage, you can refer to the table I’ve included a table on the ToolboxDIY website that you can use a reference.

Incandescent to LED Conversion Chart

Energy Savings

The next thing you’ll see is the estimated yearly energy cost. This isn’t very helpful if you don’t know what the annual cost is of a traditional bulb. Rather than using this information to determine cost savings of an LED light, you can search online for an LED savings calculator which will give you a better comparison of annual energy costs.

LED Lifespan

Next is the lifespan of the bulb. I don’t find this very useful. This can be a very misleading number. It’s a very long explanation so I won’t cover it here. You can hear all about it in our video “LED Buying Tips”. The only thing I use this for is when all other things are equal between two different bulbs. I might choose the one with a longer lifespan.

Watts

Also on the label is the energy used of the watts. This how much power the bulb uses.  A lower number means it uses less energy but it doesn’t mean it is more efficient. Efficiency is measured as lumens per watt which you may find on some labels. The more lumens per watt, the more efficient the bulb. If the label doesn’t show this number you can calculate it by dividing the lumens by the watts.

LED Light CRI

Another number you typically find on the label is the color rendering index (CRI) also known as the color accuracy. This is a measure of how accurately colors will look under this light. The higher the number the better the color accuracy. This isn’t that important to some people, but if you have a hard time differentiating your black sports coat from you navy blue one, then I would recommend using a high CRI bulb in your closet or bedroom. I don’t buy any bulbs with a CRI under 90.

LED Light Color Temperature

Last, but most importantly is the color temperature. Every bulb will have a color temperature listed as a four digit number followed by a K such as 2700K. K is short for kelvin which is the unit of measure for color temperature. The lower the number the more warm or orange the color of the light will be. The higher the number, the more cool or blue the light will be. Higher numbers like 6000K are closer to daylight during the middle of the day. I prefer 2700 to 3000 in living areas and bedrooms. In kitchens or utilities rooms, I shoot for 4000-4500k. In my workshop and garage, I go for 5000K or higher. For landscape lights, it’s really just a matter of preference. 2700K-3000K lights look a lot like incandescent and halogen bulbs. The only word of caution I have is that if you put a high color temperature bulb in a bedroom, it could actually interfere with your circadian rhythm. It has much more blue light which signals to your brain that it isn’t time to go to bed. Of course, color temperature is entirely a personal choice so use what works for you.

So that covers all the technical information you need to understand to choose the LED light that’s right for you. Of course, these aren’t the only factors you should use when choosing a bulb. If the bulb will be visible, then of course the shape and appearance of the bulb will be important to you as well.

More LED Resources:

Converting a Fluorescent Fixture To LED Tubes

Tips for Buying LED Lights