It should approximate for it but I didn't do it directly, I took a big shortcut.
Traditionally my summer bills (no heat, only cooking and hot water) over the last several NG houses have been about half of what my average usage works out to here.
As I type this however, it occurs to me that I neglected to account for the fact that my NG service always had a flat monthly service charge before the usage gets added in, while my propane service is just a flat rate per gallon. I should probably take a second run at that calculation, but if anything the difference should grow.
I asked because almost 30 years ago, I compared NG to propane costs for the first house we built, and it's was pretty even (we paid for the NG line because it was more convenient, but cost was a wash.) Propane cost more due to transportation and delivery costs (almost all trucking, no pipelines), but NG had about half the energy content, so that evened it out. I have long-forgotten the details, though. I saw you calcs showed NG at about half the cost of propane, which didn't make sense to me based on those foggy memories...
