Calculate new Lat/Lon from initial Lat/Lon plus Cartesian X,Y

How do you convert XY coordinates to latitude and longitude?

Calculate latitude and longitude using the formula: latitude = asin (z/R) and longitude = atan2 (y,x). In this formula, we have the values of x, y, z and R from step 2. Asin is arc sin, which is a mathematical function, and atan2 is a variation of the arc tangent function. The symbol * stands for multiplication.
 

How to calculate the distance between two points using longitude and latitude?

For this divide the values of longitude and latitude of both the points by 180/pi. The value of pi is 22/7. The value of 180/pi is approximately 57.29577951. If we want to calculate the distance between two places in miles, use the value 3, 963, which is the radius of Earth.
 

How do you calculate long lat?

Mark how much distance is between the southern parallel to your location. Add this to the latitude of the southern parallel to get the latitude of your location. To measure the longitude you must place the ruler diagonally on the west and east meridians with the ends of the 2 ½ minute ruler touching both meridians.