Watts to Lumens: How to Choose the Right LED Replacement Bulb Using Lumens

Posted on the 13 October 2020 by Siestalighting

Every year, lighting manufacturers bring newer, higher-efficiency lighting technologies to the market. The emergence of these technologies has led to longer-lasting bulbs, significant energy savings, and wider options. But unfortunately, what used to be a simple routine purchase has become much more complicated for many people. Back then, wattage was used to judge the brightness of a bulb, which was fine when we had old-fashioned incandescent bulbs. But now that LED bulbs have taken the center stage with different styles, technologies, energy requirements, and features, ‘lumens’ is quickly replacing wattage as the key characteristic for identifying the right bulb. Here’s what you need to know before you shop.

Check the label

Almost all the information you need about an LED light bulb can be found on the packaging, specifically on the Lighting Facts label on the back or side of the packaging. Be sure to pay keen attention to two key terms: ‘Brightness’ and ‘Light Appearance.’

Choose your desired LED Brightness

Whenever you buy a light bulb, the wattage is usually listed on the packaging (e.g., 40W, 60W, 75W, 100W). A wattage is a unit of measurement for electric power. Or in layman’s terms, it’s a measure of the amount of energy a light bulb uses. The higher the wattage, the more energy is consumed. In traditional incandescent bulbs, higher wattage correlates with a brighter bulb. However, the newer and more efficient types of bulbs use far less energy and produce the same or even more light than traditional bulbs. Therefore, wattage is no longer an accurate indicator of bulb brightness. Ideally, you should aim for bulbs with lower wattage and higher lumen (lm) rating, such as LED bulbs, which use less power and are more energy-efficient compared to older types of bulbs.

A bulb’s lumen count is the most accurate way to tell how bright it is compared to its incandescent counterpart. A lumen is a measure of visible light energy (essentially, the brightness of a light source). When a bulb has a higher lumen count, the brighter the light that is emitted. Conversely, a bulb with a lower lumen count produces dimmer light.

How to Convert Watts to Lumens

When replacing a new lighting fixture, you need to know the brightness level of the original light to purchase one that has about the same brightness – which is where the watts-to-lumens conversion comes in. If you are replacing a 100W incandescent bulb, you will need an LED replacement that produces about 1,600 lumens. A replacement for a 40W incandescent bulb should produce about 450 lumens. But how did we arrive at these estimates?

The old tungsten technology used in incandescent bulbs only had an efficacy of about 15 lumens per watt. Impressively, LED technology can produce about 60 lumens per watt. You can use this 4:1 ratio as a general rule to determine which LED bulb to choose when replacing an incandescent bulb. But please note that efficacy varies from manufacturer to manufacturer. Therefore, you should always check the Lighting Facts label and try to match the lumens. Even so, a label will sometimes tell you that an LED bulb has the same brightness as the original bulb, but sometimes it doesn’t.

Instead, use this lumens-to-watts conversion charts as a reference to help you choose the right LED replacement bulb:

LED Bulbs (Watts)Incandescent Bulbs (Watts)Lumens EquivalentBulb TypeLE (Lumens/Watt)

625375Incandescent12 – 18

1040450Halogen16 – 24

1560800LED30 – 90

19751100  

251001600  

381502600  

502003000  

Choose the Light Appearance

A bulb’s Light Appearance refers to its color temperature, measured as Kelvin (K). Of course, selecting the right Light Appearance for your space can make all the difference. Lower degrees Kelvin indicate a warmer, yellow-white light, while higher degrees indicate a blue-white light. For living room light fixtures or table lamps, select a bulb with about 2,700K to 3000K to get a warm light similar to that of an incandescent bulb. Offices/workspaces will often use this color temperature. Bathrooms, kitchens, and workspaces may benefit from cooler, bluish light (4100K – 5,000K). Daylight white color temperatures (6500K) can be used for task lighting in places like laundry rooms, workshops, and garages.  

Make your purchase and evaluate the test bulb

Now that you know how to measure the light output of an LED bulb and the ideal color temperature, you’re almost ready to buy your first one – assuming that you’ve got all the other buying factors figured out. For your first purchase, it’s okay to start small with about one or two LED bulbs. If the lights are bright and high-quality enough and produce the right color temperature, you’re good to go. If not, make notes on appearance, energy used, and brightness. If you have any questions about your purchase, one of our friendly, certified, and professional Lighting Specialists will be available to assist you.

Contact Siesta Lighting to evaluate the energy-saving LED lighting options available for your home or business

Whether for your home or business, Siesta Lighting has a wide range of LED lighting options to suit your lighting needs. Best of all, our LED lighting solutions are energy-efficient and work perfectly in restaurants, retail stores, hotels, warehouses, production facilities, and other commercial buildings. Contact us for assistance with your energy-saving calculations as well as to determine the right LED replacement bulb.