How many joules are there in a led bulb?

Since LED bulbs come in a variety of sizes there is no one answer. If we consider Watts then LED bulbs from 1 to 12 Watts are common. The higher end of quality LED lights that are commercially produced generally yield about 80 lumens per Watt. This means for a 10 Watt LED bulb your looking at 800 Lumens. This is higher than both CFL and incandescent lights. LED bulbs can save money in the long run due to the lower energy use, but they require a larger up front investment. See below for a link to an example of an LED bulb that produces 460 lumens.