Is it really necessary to save to some molecular accuracy?

[jidanni]

https://www.openstreetmap.org/user/jidanni/traces/11773992 :

Filename:	2025_03_07_14_50_08.gpx (download)
Uploaded:	7 March 2025 at 11:42
Points:	26
Start coordinate:	24.18696166666667; 120.86763833333335 (map / edit)

Is it really necessary to save to some molecular accuracy? Nanometer here.

[valerio-bozzolan]

Mandatory XKCD meme :D

https://xkcd.com/2170/

[miltonials]

Following the Precision of coordinates from the OSM Wiki

6 decimal places is enough. It gives:

• Enough presicion for the best consumer GPS
• Compact and human-readable
• Compatible with all GPX consumers

---

Disadvantages of having so much decimals

• Meaningless precision — consumer GPS hardware accuracy is 3–5 m (sometimes up to 10 m), so digits beyond 5–6 are pure noise
• Larger file size — more characters per point, multiplied by thousands of track points
• Readability — harder to visually inspect or diff GPX files
• False sense of accuracy — implies sub-millimeter precision that simply doesn't exist

[valerio-bozzolan]

Given the strong consensus I suggest to migrate (promote) this discussion to an actual issue, and propose a merge request :) Hopefully already indicating what should be the maximum amount of digits.

[jamescr]

I created the issue #706
Thanks @jidanni for your accurate contributions to OSMTracker.