Seeing Bulbs in a Whole New Light: Think Lumens

100 watt incandescent bulbs were scheduled to be banned from store shelves in the U.S. as of January 1, 2012. In mid-December, the compromise Federal budget included a measure that denies funding to enforce the 2012 ban. Even so, the phase-out is of ALL incandescent bulbs is inevitable. This article outlines how much energy incandescent bulbs use and how inefficient they are to alternatives.

Let's clear up one myth about alternatives to incandescents right away. Many think the overall look and feel of lighting as we know it will change significantly when incandescent bulbs go away. This is only partly true, as lighting engineers are well aware that people are used to and generally prefer the warm amber light of incandescent bulbs to the pure white light of many replacements. In response, lighting manufacturers are adding measures to LED bulbs in particular to make them more like the 'warm light' of incandescent bulbs.

More importantly, people need to think about light bulbs in an entirely different way in order to buy bulbs that meet specific functions. Most Americans evaluate light bulbs in terms of wattage, and clearly most understand the difference in light emitted from a 30 40 watt bulb compared a 100 watt incandescent bulb.

But watts don't measured by light intensity! Light intensity is measured by 'lumens' (or luminous flux). Watts measure how much electricity is used. The chart below compares watts (electricity used) versus lumens (light output) for incandescent, CFL (compact fluorescent light bulbs), LEDs, and halogen bulbs.

According to a package of one 100 watt incandescent bulb, the bulb emits 1370 lumens. A generic version said the bulb emits 1250 lumens. (Note: like CFLs, the performance of incandescent bulbs is negatively impacted by temperature extremes.)

Bulb Types and Lumens provided per Wattage

Incandescent Bulbs

150 Watts provide 2,600 to 2,800 lumens

100 Watts provide 1,600 to 1,800 lumens

75 to 100 Watts provide 1,100 to 1,300 lumens

60 Watts provide 300 to 900 lumens

30 to 40 Watts provide 450 lumens

Compact Fluorescent Light Bulbs (CFL)

30 to 55 Watts provide 2,600 to 2,800 lumens

23 to 30 Watts provide 1,600 to 1,800 lumens

19 to 22 Watts provide 1,100 to 1,300 lumens

13 to 18 Watts provide 300 to 900 lumens

8 to 12 Watts provide 450 lumens

Halogen Light Bulbs*

100 Watts provide 1,850 lumens

72 Watts provide 1,325 lumens

LED Bulbs

25 to 28 Watts provide 2,600 to 2,800 lumens

16 to 20 Watts provide 1,600 to 1,800 lumens

9 to 13 Watts provide 1,100 to 1,300 lumens

6 to 8 Watts provide 300 to 900 lumens

4 to 5 Watts provide 450 lumens

*Note: Halogen light is measured a bit differently than other bulbs. There also are different types of halogens and the lumens per watt vary greatly. You need to read the information on each halogen bulb package. Depending on the type of halogen bulb, estimates of lumens per watt vary greatly.

Like incandescent bulbs, halogens use a significant amount of electricity to generate heat along with light, causing the bulb's to become extremely hot. Many experts estimate that the 'wasted' electricity that halogen use to create heat versus lights is comparable to incandescent bulbs.

Rules of Thumb When Purchasing Bulbs

Can you just say 'Okay, I'll buy a 16 watt LED bulb or a 30 watt CFL instead of a 100 watt incandescent bulb? To an extent, but not necessarily. All light bulbs' packaging is required to clearly state how many lumens the bulb produces.

The US Department of Energy (DOE) recommends consumers use the following as 'a rule of thumb' when buying light bulbs.

'To replace a 100-watt incandescent bulb, look for a bulb that gives you about 1600 lumens. If you want something dimmer, go for less lumens; if you prefer brighter light, look for more lumens.

Replace a 75W bulb with an energy-saving bulb that gives you about 1100 lumens.

Replace a 60W bulb with an energy-saving bulb that gives you about 800 lumens.

Replace a 40W bulb with an energy-saving bulb that gives you about 450 lumens.

Cost Efficiency of Different Lights

While incandescent bulbs are usually the least expensive, their inefficient use of electricity/watts is the primary reason why they are being phased out. In general, CFLs are the cheapest bulbs to purchase today. But they have certain negative features, which include:

Lumens of CFLs are negatively impacted by temperature extremes.

CFLs contain mercury and are considered hazardous materials for disposal purposes.

Frequently turning CFLs on and off shortens their lifespan.

CFLs are more fragile than LEDs; LED bulbs have no filamentsLEDs turn on immediately, where as many CFLs have a slight delay when initially turned on

Some CFLs emit a low buzzing sound very annoying to some people find; others can't hear the noise. The sound varies with CFL manufacturers and the purpose for which it was designed..

The Bottom Line:

Incandescent bulbs use inefficient, obsolete technology. By the end of the decade, they won't be manufactured by China (maker of 90 percent of all light bulbs in the world) and won't be available at all within the US and most other countries.

Note: Multiple sources were used for this article including the US Department of Energy. Some information was 'averaged' as information varies greatly depending on the source and the date information was compiled. Data was confirmed by looking at light bulbs at a major home center. We suggest readers visit for more information about energy efficiency of various light bulb alternatives and why incandescent bulbs aren't aren't the best choice.