Here you go. Measured from bottom to middle of air relief valve.
DE2420 = 32" -- 3lb DE
DE3620 = 34.1" -- 4.5lb DE Edited to correct model number. Thanks Paul
DE4820 = 40.1" -- 6lb DE
DE6020 = 46.1" -- 7.5lb DE
DE7220 = 52" -- 9lb DE
When you say measure form the bottom are you referring to the ground or bottom of the filter where it starts to curve under? Hope that makes sense. Been looking to determine what size my DE filler is and stumbled across this post. Thanks