Replacing HID Lumens with CKRA LED Lumens

When calculating the required lumens needed to replace an HID fixture with an equivalent LED fixture use the following formula to calculate:
Initial lumens x (.5) = A, A x (.66) = Replacement lumens needed  
Take the initial lumens produced from the HID fixture and cut it in half. HID lamps project 360 degree light, 50% of the initial lumens are lost to the reflector or the back of the fixture.
Take the remaining half of light output, the 180 degrees of light being thrown forward from the fixture and reduce that by 1/3. The remaining two thirds of Lumens are call useable lumens they are the actual lumens used to light the targeted area, the other 1/3 is loss ambient light.
e.g. A 400 watt MH fixture emits 36,000 lumens.36,000 x (.5) = 18,000, 18,000 x .66 = 11,880) Approximate 12,000 lm of light needed for replacement).
This calculation does not take into effect the loss of lumens due to degradation of the HID light source which could reach as high as 50% within the first year of using of the bulb. Degradation of LED lamps are less that 30% for the full life hours of the lamp giving a more consistent and brighter light output than any equivalent HID light source.
Refer to standard Electrical Lighting Codes to determine proper Foot Candle requirements for lighting application.