For too long we have been buying light bulbs based on their energy consumption (measured in watts), not the amount of light they produce. With energy-efficient lighting products, such as LED light bars, decorative bulbs and work lights, we can stop worrying about watts and make a bee-line to brightness. Lumens measure brightness—the amount of light coming from the bulb. Watts equate to energy consumption, but with energy-efficient LED light bars, home bulbs and work lights, the energy consumption barely registers. Footcandles and Lumens
The amount of light that falls on one square foot of surface area one foot away from the source is a “footcandle,” and that, conveniently, is one lumen. All the measurement units work together to help you select bright bulbs for just about any need. A footcandle and a lumen make sense; watts, which only measure how much energy the bulb uses, do not make a lot of sense for measuring desired results. Watts Wrong
Watts are a leftover measurement from an era of inefficient, heat-generating illumination. Before the age of LED light bars, work lights and household bulbs, everyone learned an awkward equivalence of watts and brightness. You bought a 60-watt incandescent bulb for reading, and lower wattages for softer light. You bought high wattage bulbs for tall rooms, for example, because the amount of light falls off in inverse proportion to distance. Think about it—a car headlight 100 feet away is far dimmer (one-fourth as bright) than one 50 feet away. A bulb at the top of a cathedral ceiling in your living room is illuminating a lot less than the same bulb in a desk lamp.
Wattage only measures how much energy goes in, not how much light comes out. Lumens are measures of actual brightness. Measuring the light actually produced by your LED light bar, work light, or decorative fixture is far more helpful than measuring the costly energy going into the bulb.
Lumens are, in fact, the natural unit to use for brightness. Think of apples, sold by the pound, or soda, sold by the liter. Light brightness is best compared by the lumen.
For LED driving lights, consider high lumen numbers (4,000 lumens and higher). This would be far too bright for other purposes, of course. A work light at 900 lumens provides ample lighting. Around your home, consider replacing 40-watt incandescent bulbs with 450 lumen LED bulbs.