title: How to translate a given coordinate into a bounding box of "diameter" x?
body: <p>For example, I have a latitude and longitude in decimal format (as opposed to Degrees-Hours-Minutes like lat=44.1° 9.5' 30''). To search for nearby objects, I must specify the search "radius" as a rectangle with four values:</p>
  
  <pre><code>north = 44.1;
  south = -9.9;
  east = -22.4;
  west = 55.2;
  </code></pre>
  
  <p>Is there a formula or rule of thumb how to convert decimal lat/long values into a rectangular bounding box, such that the given latitude/longitude is in the center of that box?</p>
  
  <p>Must I fiddle around myself with a WGS84 ellipsoid algorithm or are there open solutions to the problem?</p>