Indeed a good question! Most of us dont know the number of LED lights we should use in a room to make it sufficiently illuminated. The outcome is that the room either becomes over illuminated or less illuminated than the requirement. Here are few expert advice that can help us decide the number.
Number of recessed lights that one needs to light a room.
Downlights can also be used in bathrooms, just that the number would depend on the room size.
Sometimes the number can also help us decide the type of LED light to be used in a room.
More helpful when you are building a new home.