Geohash: How much hash length is enough

Question

For an application that needs to store Geographical location of a person in the form of Geohash, how much hash length (in characters) would be enough?

The code located here (referred in Wikipedia article on Geohash) says:

    #define MAX_HASH_LENGTH 22

But they haven't mentioned any reason for that.

bmorin · Accepted Answer · 2015-07-08T12:02:52.723

0

Some justification can be found on other topics:

geohash-and-max-distance

geohash-string-length-and-accuracy

To localize a person, you would probably need a one-meter accuracy. 10 characters should be enough.

edited Jul 08 '15 at 12:02

answered Jul 08 '15 at 11:53

bmorin

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You mean 10 characters? – Atul Jul 08 '15 at 11:55
Yes its [here](https://stackoverflow.com/questions/13836416/geohash-and-max-distance) Thanks! – Atul Jul 08 '15 at 12:04

score 0 · Answer 2 · answered Jul 15 '15 at 21:37

If you are looking at something like building or house locations (associated with a person) you could go as small as geohash of length 8.

A geohash with a string value of 8 characters gets you to within +/- 20 meters of a location, a geohash of 9 characters gets you with +/- 5 meters. See a full list of information on geohash lengths on wikipedia

Geohash: How much hash length is enough

2 Answers2