How accurately should I store latitude and longitude?

Question

I was reading this question here:

What datatype to use when storing latitude and longitude data in SQL databases?

And it seems the general consensus is that

Answer 1

Don't store floating point values. While you might assume they are accurate, they are not. They are an approximation. And it turns out different languages have different methods of "parsing" the floating point information. And different databases have different methods of implementing the value approximations.

Instead, use a Geohash. This video introduces and visually explains the Geohash in under 5 minutes. The Geohash is BY FAR the superior way to encode/decode longitude/latitude information in a consistent way. By never "serializing" the approximated floating point values of a longitude/latitude into database columns and instead, using a Geohash, you will get the same desirable round trip consistency guarantees you get with String values. This website is great for helping you play with a Geohash.