I have a bathroom wall mounted mirror ( approx 20 inch x 15 inch) I use for shaving that tends to fog up completely after I shower due to the steam.

Do all mirrors fog up? Are there solutions to this problem? ( Other than just switching to cold showers! :) )

The mirror is fairly old maybe 20 years , would that affect the fogging characteristics?

A retrofit or DIY solution would be great but worst case I would just change the entire mirror.

  • 1
    gently warm the mirror to above the dew point. heating kits are available for car mirrors...
    – Solar Mike
    Sep 27, 2023 at 4:22

2 Answers 2


If your bathroom gets humid enough from a shower that your mirrors fog up, you likely don't have enough ventilation. The mirror fogging up is the least of your problems, you might get moisture-related problems like mildew and mold growth. If you have a vent fan and don't run it during a shower, run it during a shower and for at least 30 minutes afterwards. If you do have one, it might be a good idea to upgrade to a more powerful one. My bathroom mirror doesn't fog up from hot showers if I run the fan.

If you don't want to take that advice and it's gotta be a non-fog mirror, there are things you can apply to glass to eliminate (or at least reduce) fogging. The same Rain-X interior anti-fog solution they make for windshields should work on your mirror. Glass is glass. Age of the mirror shouldn't matter and another mirror will fog the same way (unless perhaps it's got some special anti-fog coating); because, again, glass is glass.

  • Non-glass mirrors, with less thermal mass, may fog less but also don't give as good a reflection. My solution is just to swipe a towel across the mirror.
    – keshlam
    Sep 27, 2023 at 3:53

Heated Mirrors exist to solve your problem

Mirrors fog because the temperature of the glass is less than the dew point of the bathroom. While it is possible to ventilate your room enough to avoid this, my experience is that all bathroom mirrors fog after a hot shower. I have a bathroom where I can keep the mirror fog-free via taking a relatively cool shower and running the exhaust fan, but my wife, who takes showers of a temperature appropriate for boiling crabs, will always have a fogged mirror.

Anti-fog mirrors are heated to keep their temperature above the dew point. The ones commercially available seem to have lights built in, which makes sense because they need power anyway.

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