The old days of choosing light bulbs by wattage are over. With today’s modern LED bulbs, we instead need to focus on lumens. But what is a lumen? We’ll explain that, and then you can use our lumens to watts conversion chart to select the right LED bulb every time.
How to Convert Lumens to Watts
Step 1: Understand Watts
Watts are a measure of energy consumption. When we pay our electric bill, we pay for the number of watts we use. A 60-watt bulb consumes 60 watts of energy. Since we used 60-watt incandescent bulbs for so many years, we associated a certain level of brightness with 60 watts. But we can’t do that anymore, since LED technology produces more light while using fewer watts. Instead, we need to use lumens.
Step 2: Understand Lumens
A lumen is a measure of visible light energy. The higher the lumens, the brighter the light. All lighting manufacturers are starting to tell us how many lumens are produced by each of their products. We see these lumen numbers on the Lighting Facts labels found on all new LED bulb packages. It may take a while to get used to using lumens instead of watts, but it’s important in order to make the best lighting choices.
Step 3: Understand Efficacy (Lumens/Watt)
Now that we understand watts and lumens, we can use both terms to come up with lumens per watt or “efficacy” (or “luminous efficacy”). This is a measure of how well a light source converts energy (watts) into light (lumens). The old technology of tungsten incandescent bulbs only had an efficacy of about 15 lumens/watt. LED technology typically produces 75-110 lumens/watt. So, LEDs are about 6 times more efficient at producing light than incandescent bulbs. Use this 6:1 ratio as a rough guide when selecting an LED bulb to replace an incandescent bulb.
For example, if you wanted to replace a 30-watt incandescent bulb, what wattage LED bulb would be roughly equivalent? Using the 6:1 ratio, simply divide 30 watts by 6 to get 5 watts. But efficacy varies wildly from manufacturer to manufacturer, so it’s best to check the Lighting Facts label and try to match lumens. Also, a label will sometimes (but not always) tell you that an LED bulb has an equivalent brightness. Refer to the charts below for a ready reference. Finally, please note that all VOLT® outdoor LED light bulbs have the incandescent or halogen equivalent wattage displayed on their product pages. We make switching to LED landscape lighting easy!