There is no standard watt-to-lumen conversion value. The amount of lumens per watt depends on the type of light source that is being measured. A general incandescent light source is measured at 10 to 15 lumens per watt.
Watts measure the amount of energy required to light a product, whereas lumens measure the amount of light produced by the product. The more lumens in a light bulb, the brighter the light. A halogen lamp may have 15 to 25 lumens per watt. A compact fluorescent light can produce 50 to 75 lumens per watt, and LED lamps produce 50 to 100 lumens per watt.