Stop Worrying About Turning the Lights Off When You Leave the Room—It’s Not Actually Saving Money

Household rules vary quite a bit from home to home, but there’s one that most of us grew up hearing over and over again: “Turn off the lights when you leave the room!” If you had parents who were at all concerned with conserving energy, or, more likely, lowering the number on their energy bills, then you probably heard them frequently repeat this rule—and maybe even scold you when you left your bedroom light on. However, times change, technology improves, and the rules that applied back then don’t always apply today. With modern intel from the Department of Energy, we’re rethinking everything we thought we knew about leaving the lights on and “wasting energy.” Here’s what you need to know and how much you really need to worry about turning off the lights.

Should You Turn the Lights Off When You Leave the Room?

The idea that you should turn off the lights whenever you leave a room is based on the thinking that the longer you leave on a light, the more energy (and therefore, money) you’re wasting—and that makes sense. However, according to the Department of Energy (DOE), “All lightbulbs have a nominal or rated operating life, which is affected by how many times they are turned on and off. The more often they are switched on and off, the lower their operating life.” That means that instead of worrying about how long you leave the lights on, it may make more sense to think about how often you turn the lights on and off. This is because the savings on your energy bill from turning the lights off can be pretty minuscule, and the price to frequently replace worn-out light bulbs can exceed that cost.

So, do you really need to turn off the lights every time you leave a room or aren’t using it? The answer is sometimes yes, but oftentimes no—and it mostly depends on the type of lightbulbs you use.

How Your Lightbulbs Determine Whether or Not You Should Turn Off the Lights

According to the DOE, the cost-effectiveness of turning the lights off when you leave the room depends on both the type of light bulb and the cost of electricity. In general, however, the DOE states that the more energy-efficient a lightbulb is, the longer you can leave it on before it’s cost-effective to turn it off.

Here’s a rundown of the different common types of lightbulbs and how concerned you should be about turning them off when not in use.

• Incandescent: These are the least efficient lightbulbs, so you should turn them off whenever they aren’t in use.
• Halogen: While more efficient than incandescent bulbs, halogen bulbs use the same technology and aren’t as efficient as CFL and LED bulbs, so they should also be turned off when not in use.
• CFL: CFL bulbs are very efficient, and their operating life is affected by the number of times they’re switched on and off, so you should think twice before turning them off. As a rule of thumb, DOE suggests leaving these lights on if you’re leaving a room for only 15 minutes or less, and otherwise turning them off.
• LED: LED bulbs are both highly efficient and are unaffected by how often the lights are turned on and off. So, whether or not you leave these lights on or off when you leave the room effectively doesn’t matter (although you’ll still want to turn these lights off if you’re leaving for the day).

Since CFL and LED bulbs are widely popular these days, most of us don’t have to worry very much (or at all) about turning the lights off every time we leave a room. If you want to calculate the exact energy savings versus costs for your light bulbs in your home, the DOE breaks down an equation in its explainer here. But just know that if you use LED bulbs, leaving on the light for several hours makes a difference of pennies, not dollars, on your energy bill—so, it’s not really worth the stress or the household fights.