Four that I use on a regular basis: CF road bike for fast road rides, gravel bike for gravel, winter road riding, and maybe cyclocross (!), steel single speed for commuting, general utility/transportation riding, and sometimes road cycling, and old MTB for deep winter (I live on the Wisconsin/Minnesota border.)

In addition, I have a cruiser that needs to be sold and two somewhat beat up vintage frames that should probably be retired and enough parts to turn them back into complete bikes. There's also my husband's nice FG bike that's been in the basement for a while.

At the moment, my winter beater has been beat and needs to be replaced. I really want to get another beater AND a fat bike, which would put 5 bikes in regular rotation