How Many Decimal Places Do I Need to Store Latitude and Longitude for Accurate Location Data?

Precision of Latitude and Longitude Storage

When storing latitude and longitude data, the desired accuracy plays a crucial role in determining the number of decimal points required. The premise is that the data accuracy corresponds to the distance represented by each decimal place.

Given that Google's API returns latitude and longitude coordinates with 6 decimal places, let's consider the distance represented by this level of precision.

According to the Wikipedia reference (provided in the answer), at the equator, each decimal place represents the following distances:

- 1 decimal place: 11.1 km
- 2 decimal places: 1.11 km
- 3 decimal places: 111 m
- 4 decimal places: 11.1 m
- 5 decimal places: 1.11 m
- 6 decimal places: 0.111 m

If the desired accuracy is within 50 feet (approximately 15.24 m), then you would need to store the latitude and longitude to at least 5 decimal places. This level of precision would provide an accuracy within 1.11 m.

In general, for the desired accuracy, it's recommended to store the following number of decimal places:

- 0 decimal places: ~6000 miles
- 1 decimal place: ~600 miles
- 2 decimal places: ~60 miles
- 3 decimal places: ~6 miles
- 4 decimal places: ~0.6 miles
- 5 decimal places: ~1.11 m

By understanding the distance represented by each decimal place, you can accurately determine the number of decimal points needed to store latitude and longitude data, meeting your specific accuracy requirements.

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