[sokoloff]

It takes around 1/5th kWh to boil a liter of water, or around $0.04 for me (in a place of fairly expensive electricity for the US).

How much cheaper would gas have to be for me to choose gas over electric? Probably $0.25/liter or more cheaper.

[morsch]

People I know with gas or induction stoves use it to boil water because it's faster. This must be doubly true in the US with it's comparatively weak power outlets.

[ncmncm]

I measured. It takes fully twice as long on a gas range burner, with a wide, flat-bottom kettle.

[morsch]

I have no reason to doubt your result for one specific electrical kettle and one specific gas stove.