ZIP Code Latitude & Longitude

Location, Location, Location is what so many applications are about, especially mobile.

Overview

Recently we looked at a very popular ZIP Code Database site's demo data and found the following:

  • 56% of the latitude / longitude coordinates were over 3 miles off
  • Almost 10% were over 15 miles off!
  • About 4% were off by over 20 miles!

Lat/Long Matters

Having accurate latitude / longitude coordinates is important. They are used in dealer / store locators and in many mobile apps.

We've seen a sales rep locator point to the wrong rep. We've seen a locator show a store location which was actually in front of a competitor's store.

Both the ZIP Codes and the locations need to be accurate. Your sales depend on it!

Population-based Centerpoints

Many ZIP Codes have large areas of unpopulated areas such as parks, lakes, golf courses, airports, etc. Most ZIP Code latitude and longitude centerpoints are the physical center of the ZIP. We know of only one exception and that's our company, GreatData.com. When we manually verify the center of a lat/long (which we do continually), we look for where the main population center is located.

There are challenges in assigning a ZIP Code centroid. Sometimes they cover hundreds of square miles with towns on each side of a mountain range, so a centerpoint would be in the middle of the mountains. Always look for manually verified lat/long coordinates, rather than computer generated.