You could also try out the
nuke calculator in the stardestroyer website as stated in our explosion page instructions and keep inputting the megaton yield until it matches your radius value of near-total fatalities (Granted it's in metric AKA meter and kilometer but nothing a converter can't fix)
Using the site, in order to achieve a 2 mile radius worth of near-total fatalities, You'll need 1.532 megatons of TNT (Also
Low 7-B,
City level), pretty damn close to DDM's results.