Say I have a table lamp that states (via a slightly scary sticker) that it takes a 60W max bulb. Of course, that was based around incandescent wattages.

Is there any risk with putting in a CF bulb with a higher brightness but lower wattage? e.g. if I put a 23W CF (which is a 100W incandescent substitute) into this lamp?

Does anything matter besides wattage here?


2 Answers 2


No, the wattage is based on heat dissipation, so as long as the actual wattage of the bulb you are putting in is less, you're good to go.

  • 1
    There may be some physical limitations of an actual 60W CFL (if one even exists) bulb fitting in the lamp fixture, due to size.
    – HerrBag
    Mar 14, 2013 at 13:10
  • There are in fact CFL bulbs that fit in a regular socket that use more than 60w -- homedepot.com/p/t/…
    – ShoeMaker
    Mar 14, 2013 at 13:17
  • The question specifically stated that the CFL had lower wattage.
    – Michaelkay
    Mar 14, 2013 at 16:30
  • 1
    @ShoeMaker MUST HAVE! You've now ruined March's reno budget for me.
    – Jason
    Mar 14, 2013 at 21:03
  • @Michaelkay, HerrBag's comment questioned the existence of a larger bulb... That is what my comment was in response to. :)
    – ShoeMaker
    Mar 14, 2013 at 23:36

What matters is clearance and airflow around the ballast in the base of the CFL.

CFL lamps that run in environments where airflow cannot take away the excess heat will suffer a much shorter lifespan. The higher the wattage, the more heat they will generate, though much reduced from what using an over-wattage incandescent (which can create a fire hazard) will generate.

So, basically the heat danger and extra current from using a too high wattage incandescent bulb is not present, but the CFL might, in the wrong fixture, be a danger to itself.

The whole wattage equivalent thing is because we've come to equate brightness with power dissipation, not the lumens produced or the efficiency in lumens per watt.

It will take 4 1/3 CFL lamps at 23 watts each to equal the power that an incandescent 100W bulb will require.

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