Are you updating your light bulbs, but not sure how bright you need them? Or how many bulbs your room needs?
You’re not alone in the confusion. It can be difficult reading the package in the hardware store and understanding what the bulb will do for your home.
This post will briefly touch on how lumens work and then guide you on how to make sure you have the right light for each room in your house.
What Are Lumens?
With major innovations in lighting over the past twenty years, bulbs have become much more efficient. That’s great news for your electric bill and the environment! But a side effect is that watts are no longer a good measurement for brightness.
Watts measure the amount of energy used by the bulb. When all bulbs were incandescent, this also indicated brightness– the higher the watts, the more energy used, the brighter the bulb.
But with more efficient bulbs, like halogens and LEDs, much less power is used while still producing bright light. So a 40 watt incandescent light gives off the same light as an 8 watt LED!
So how will shoppers know that an 8 watt LED will replace their 40 watt incandescent? Instead of measuring power use, lumens measure brightness. Now no matter the energy efficiency, you can compare bulbs apples to apples.
How Many Lumens Do I Need?
So how many lumens do you need for your space? To calculate the right lumen range, you need to know the square feet of the space and the proper foot candles for the area.
The square footage of your room will help you know how much light you need– the bigger the space, the more light you need. To find out your square footage, simply measure the length and width of the room, then multiply those two numbers.
For example, if your room is 10 feet by 12 feet, your room is 120 square feet (10×12=120).
“Foot candle” is a less familiar term, but it means the brightness of a light source from one foot away. The target foot candle range will depend on the activity of the room. For workspaces like kitchens and offices you’ll want more light (more foot candles), and for bedrooms and dining rooms you’ll want less light (fewer foot candles).
Once you have the square feet of your room and the target foot candles, then you can determine how many lumens you need. Simply multiply your square feet by the desired foot candles!
Let’s say that your bedroom is 120 square feet. Multiply 120 by 10 for the low end and by 20 for the high end of the target zone.
120 x 10 = 1200
120 X 20 = 2400
Now you know that you need between 1200 and 2400 lumens for your bedroom!
Simple Cheat Sheet
If you don’t want to worry about foot candles, here’s a chart with a general estimate of how many lumens you need per square foot per area of your home. Remember, these calculations help determine the total light a room needs. But you’ll often concentrate light above tables, countertops, or a desk.
So if your living room is 15 feet by 20 feet, your total square footage is 300 (15 x 20 = 300). Then multiply that by the recommended 10 lumens to get a minimum of 3,000 lumens for your living room (300 x 10= 3,000).
How Many Bulbs Do I Need?
It may seem overwhelming to need a few thousand lumens for your room. Don’t worry– you will still use relatively few bulbs to get all the light you need. For reference, an 8 w LED bulb will give off about 450 lumens of light.
With just a few bulbs, you’ll have all your lighting covered. Put three in the ceiling fan, add a lamp with one bulb, and you’re done!
Proper lighting is essential to a fully functioning home– but it can be challenging to nail balanced brightness, great fixtures, and a budget! Contact the experts at Aim Lighting for advice on your projec