You cannot convert latitude directly into feet. However, you can convert differences in latitude into feet. We can then discuss these distances first in nautical miles, then miles and then finally feet. These distances represent a direct north and south line without any east or west direction included.
Find the difference between the two latitudes. For example, from 42 degrees North latitude to 46 degrees North latitude, the difference is 4 degrees.
Convert the degrees of latitude into its smaller component called minutes. There are 60 minutes in one degree of latitude. Therefore, there are 240 minutes in the above example.
Convert the minutes to nautical miles. One minute of latitude is equal to one nautical mile. In the example above there are 240 nautical miles in 4 degrees.
Convert nautical miles to statute miles. One nautical mile is equal to 1.15 statute miles. In the example above, 4 degrees would be equal to 276 statute miles.
Convert statute miles to feet. One statute mile is 5,280 feet. In the example, 4 degrees would be equal to 1,457,280 feet.
The formula for degrees of latitude to feet, where D is the number of degrees and F is feet is: F = D x 60 x 1.15 x 5280
or simplified F = 364,320 x D