Here is an alternate gear calculator, preloaded with many IGH.
http://gear-calculator.com/?GR=SNI8&...&SL=2.6&UN=KMH
You can also choose for it to display ratios or other common metrics.
A 46T chainring with a 23T rear cog on a Shimano Alfin 8 gives you ratios from 1.05 to 3.23.
A 46T chainring with a 19T rear cog on a Sturmey Archer AW (3 speed) gives you ratios from 1.82 to 3.23.