MySQL PHP zip code comparison specifically distance

Question

I\'m trying to figure out what would be the most efficient (with respect to load time) to compare the distance between one zip code (which the user provides) and a whole bun

Answer 1

In Javascript:

var R = 6371; // km
var dLat = (lat2-lat1).toRad();
var dLon = (lon2-lon1).toRad(); 
var a = Math.sin(dLat/2) * Math.sin(dLat/2) +
        Math.cos(lat1.toRad()) * Math.cos(lat2.toRad()) * 
        Math.sin(dLon/2) * Math.sin(dLon/2); 
var c = 2 * Math.atan2(Math.sqrt(a), Math.sqrt(1-a)); 
var d = R * c;

where d = distance between two points

This is the Haversine formula.