China lighting factory led downlight 900 lumens

How many watts for 900 lumens led downlight?

It would be 9-10w. If the LED lumen output is 120lm/w, CRI 80

80% lighting dissipation, the finish light output lumen will be 120×80%=96 lm/w

Based on 96lm/w, the power for led downlight would be 9-10w.