The package says its 35 Watts but really it cycles between 62 and 36 watts.I can't complain because of the light it puts out for the amount of wattage it uses. The only problem I have is it's not UL certified.I used the P4460 Kill-A-Watt meter set to watts and a standard 120v, 100-watt (1270 lm) incandescent bulb with an output of 92 watts as my control in my testing.The GE 72 watt, 1270 lumens light bulb that replaced the 100-watt incandescent bulb also cycles between 113 to 66 watts.Since I'm new to these Sansi LED bulbs, I will see how they are when I get my first electric bill, but I will still pull random LED bulbs for testing to see if the wattage is still in range as they were when first installed.Conclusion: It doesn’t take much for some part of the electronics to go haywire and draw a bit more wattage and before you know it your electric bill went up $40.A great bench light bulb!Love the brightness. Hopefully it will help save energy use and money.This bulb is tremendously bright and a great value. Would recommend!BRIGHTI like this bulb it has remarkable LED bulb efficiency, tons of light with low power usage. Pleasant bulb shape. Instant on, no delay, no fan. Daylight to slight bluish color.6500 lumens at 35 watts is a phenomenal 186 lumens per watt. This is the highest efficiency LED bulb I have to date. It is an incredible jump in efficiency. Just 3 years ago LED bulbs for my home were in the 80 to 100 lumens/watt range. Then a little more than a year ago I started finding ones in the 120 to 140 lumens/watt range. Now this one at 186 lumens/watt. Unbelievable, it is more than twice as efficient than the ones I bought only a few years ago.How bright is 6500 lumens? The old 100 watt incandescent is my standard reference point. They are in the 1500 lumens range. This bulb has 4.33 times as much making it equivalent to a 433-watt incandescent or a little more light output than four, 100 watt incandescent bulbs and for only 35 watts input power. Keep in mind that the perceive brightness is not directly proportional to the increase in lumens. It takes about a 4 fold increase in lumens to perceive a doubling of brightness.Form factor. This bulb is larger than a standard A19 bulb but it has a nice rounded shape unlike the corn-row bulbs that never seem to work well in existing fixtures these fit well. Listing says it is A21 size but it is much larger. A21 means the diameter is 21 eights of an inch or 2.625-inches in diameter. These are 3.15-inches. There is no standard “A” size bulb that corresponds. Measure your space to make sure you have room.The bulb does say “Not for use in ENCLOSED luminaires”. As with all LED Bulbs, heat is a killer. The light generates heat but most of the heat comes for the transformer used to change 120VAC to the DC voltage required for the LED chips. I try to make sure my LED’s get plenty of air circulation. Old incandescent bulbs didn’t have a problem inside enclosed fixtures but put an LED in the same place and it won’t last. The cooling holes on this bulb run from the base thru the top of the bulb. Blocking this flow path will shorten the life. On my bathroom fixtures I lowered the glass shades to provide an air gap at the top, giving the heat generated a path to escape.Overall: Fabulous LED efficiency in a nicely shaped bulb with high lumen output. I would buy again.