Once you know the right brightness, you can then look at the lumens-per-watt rating to find the bulb that’s most energy efficient. Simply put, if you need more light but want to save on energy costs, you have to find a light bulb that provides more lumens at low wattage. A light bulb that provides higher lumens at a low power wattage is energy-efficient. This figure is a useful way to measure the efficacy of lighting products by measuring the total light output in Lumens divided by the. Under the new system, when shopping for a light bulb, you should first look for the bulbs that produce the number of lumens you need. This means that lumens are equal to brightness, while watts are equal to energy usage. Like miles-per-gallon in a car, the lumens-per-watt rating measures how much light that particular bulb produces per watt of power used, which tells you how energy efficient it is. If you’re choosing bulbs for task lighting, look for bulbs with 1000 lumens or more. To help you get an idea of the lumen scale, a standard 60-watt bulb puts out around 750-850 lumens of light. How many lumens are in a watt Because lumens measure brightness and watts measure energy output, there is no simple method for converting wattage to lumens. One lumen is approximately equal to the amount of light put out by one birthday candle that’s one foot away from you. Lumens are a much more accurate measurement, because it tells you how the light actually performs, regardless of the source that produced it. Lumens measure the amount of light created by a bulb, whereas watts measure the energy used by the bulb to produce lumens. Lumens, on the other hand, actually measure the amount of light being put out by the bulb. The terminology used to describe light bulbs is changing as incandescent bulbs are phased out by law.