How Do You Calculate Lumens Per Watt?
Lumens per watt (or LPW) is an efficacy rating given to light bulbs to determine how much light they produce for each watt of energy they use. When you shop for produce at the market, you look for the best deals for a pound of fruit or vegetables. When you’re shopping for light bulbs, you should look for ones that produce more light with less energy. Light bulbs with high efficacy ratings mean more savings on your power bill. Calculating LPW requires using the simple mathematical formula. Lumens are the amount of light produced by a bulb. Find the number for lumen output on the light bulb’s box. Wattage is the amount of electricity needed to light the bulb. The higher the wattage is, the brighter the light will be. You can find the bulb’s wattage written both on the box and on the bulb itself. Divide the light bulb’s lumen output by the number of watts the bulb needs. For example, a 100-watt light bulb usually has 1800 lumens, so the LPW is 18.
