A 5 watt LED bulb is equivalent to the traditional 40 watts bulb. However, the light output of LED lights continues to fluctuate year by year. For instance, a 10 watt LED lamp delivers a certain light intensity in the current time, which will drop to 8 watts in a year, and is likely to drop to just 2 watts in four years. Besides that, you do not have to look at the chart online every time you want to know the LED wattage. You can just divide the number of watts of incandescent light by ten, and it will give you approximate watts of the LED light.