A wide variety of GPS receivers are available on the market today. They vary considerably in accuracy and sometimes are designed for specific and technical applications. Most GPS receivers can be used to map something of interest for personal use. However, only high-quality GPS receivers are adequate for making maps that are used for official purposes that require high accuracy (such as a lot or property boundary that a government agency might use).

GPS receivers are generally broken into three categories, based on their accuracy:
1. Recreational grade GPS receivers are sold at most box stores and over the Internet. They are the least expensive and are generally accurate to within +/- 25 feet (7.6 meters). These units generally run in the $100 to $600 range and are the grade most often purchased by the public.

2. Mapping grade GPS receivers are generally sold by "high end" and licensed resellers. These GPS receivers are typically not as user-friendly as the recreational GPS. Although mapping grade GPS units can be accurate to within a meter (~3 feet), they are considerably more expensive than recreational grade receivers (~$1,000 to $3,000). Mapping grade GPS receivers are most often used by government agencies, researchers, and other users who require more accurate and dependable coordinate fixes than a recreational GPS can provide.

3. Survey grade GPS receivers are the most accurate but by far the most expensive GPS units available. They are accurate to within a centimeter and can cost in the tens of thousands of dollars. These GPS receivers are most often used by professional surveyors and are used primarily for highly accurate measurements of a single point.

It is very important that you carefully evaluate your application needs when choosing a GPS receiver. If your needs dictate very high accuracy or survey-compliant measurements, the more accurate GPS receivers will be necessary. For most personal use of GPS receivers, recreational grade should provide more than enough accuracy.