FWIW, my 26" wheel Rohloff bike with a 38/16 gear set, and my Brompton with a 3 speed hub, with a 15t cog ,
16-1 3/8" wheel,
and a 54t chain-ring , on the Mountain drive crank (equivalent to a 21.6t chainring in low),,
have the same low gear , equivalent to about a 17" wheel, if a unicycle..