dont think it works like that. lumens or kelvin, you cant just add them togeather...lumens is brightness, think about a room with a light on inside with the door open just a crack(you are standing outside) now add 1 more light of the same spec....the light is not 2x as bright comeing thru the crack in the door...it is brighter but not 2x so you will have more lumens but you cant simply add them all up. i could be wrong but i know kelvin dosen't work like that either. if it did i would have 78,000k for veg and thats un real. a light meater is the only real way to determine your lumens an for kelvin idk unless you have only 1 light or multipul of the same exact light then it would just be 1x whatever is on the box