Frequently asked questions

Q: Why are the latitude and longitude values different from some of your competitor's values?

A: One first needs to understand that a latitude/longitude coordinate pair defines a precise point on the earth. However, in the real word, ZIP Codes are regions -- irregularly shaped regions at that -- and cannot be defined accurately by a single point.

The situation is much like expecting North Dakota to have a single latitude/longitude coordinate. North Dakota isn't a point on the earth. It is a region -- an area. Regions can't have a single latitude/longitude value. If you do find North Dakota represented by a single latitude/longitude pair in some database, it is someone's attempt to judge what they believe to be the center of North Dakota. The same holds true of ZIP Codes. ZIP Codes are regions. ZIP Codes are areas, not a pin stuck in a map . Consequently, it is up to the eye of the beholder (or in this case, the company compiling the data) to choose what they think is a representative latitude/longitude value for the ZIP Code in question.

Here's an example. Look below at image representing ZIP Code 60634. The lime green colored region is the actual area representing 60634. Place your finger on the screen at a point representing 60634.  See the problem? You could place your finger anywhere within the lime green area and be correct. You can therefore see why you will find variations from one company to another in respect to the latitude/longitude value they use to represent a ZIP Code.


If you have any additional questions, please contact us.

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