given km

1000 m/km
100 cm/m
1   in/2.54 cm
1   ft/12 in
1   mi/5280 ft


1000*100/2.54/12/5280 = 0.621371

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min and max earth-moon distances:

363104 km * 0.621371 mi/km = 225622 mi
405696 km * 0.621371 mi/km = 252087 mi
delta = 26465 miles
average (non-weighted!) (225622 + 252087)/2 = 238854

diameter: 3476 km equatorial, 3472 km polar

3476 * .621371 = 2159 mi
3472 * .621371 = 2157 mi