--- title: "\"Precise\" Is Less Precise" description: Set Meshtastic's map report precision to 32 and the firmware quietly uses 14, about 0.9 miles. 15 gives about half a mile. Here is the bits-to-distance table. image: https://willcurran.com/hubfs/will-curran-brand/precise-is-less-precise-cover-nolane.png --- [Skip to content](https://willcurran.com/blog/precise-is-less-precise#main) [Will Curran](https://willcurran.com/) [Home](https://willcurran.com/) [Portfolio](https://willcurran.com/portfolio) [Press](https://willcurran.com/media) [Blog](https://willcurran.com/blog) [Favorites](https://willcurran.com/favorites) [Speaking](https://willcurran.com/speaking) [Consulting](https://willcurran.com/consult) [Hire Will](https://willcurran.com/hire) [Writing](https://willcurran.com/blog) Builds — "Precise" Is Less Precise [Subscribe](https://willcurran.com/blog/subscribe) Builds # "Precise" Is Less Precise ![](https://willcurran.com/hs-fs/hubfs/will-curran-brand/will-curran-avatar.jpg?width=44&height=44&name=will-curran-avatar.jpg) Will Curran Aug 30, 2026 · 3 min read On this page ![An abstract dark grid of nested squares, each half the size of the last, with an orange dot centred in one of the larger squares, next to the title Precise is less precise and the line set 32, get 14.](https://willcurran.com/hs-fs/hubfs/will-curran-brand/precise-is-less-precise-cover-nolane.png?width=1600&height=900&name=precise-is-less-precise-cover-nolane.png) In Meshtastic, the map report has its own position precision setting. Set it to 32, the number that means full precision on a channel, and your node shows up on the public map *less* precisely than if you had picked 15. The firmware only accepts 12 to 15 there. Anything outside that range, 32 included, is quietly swapped for 14: a blur of about 0.9 miles. 15 would have given you about half a mile. ## Two knobs that look alike The channel setting decides how exactly your position goes out over the mesh, and on a private channel 32 really does mean full precision. The map report setting decides what your node tells the public map over MQTT. Same kind of number, different rules. In the firmware's MQTT code, a map report precision below 12 or above 15 logs a warning and falls back to the default of 14. The comment above that check says it "removes obtusely large radius and privacy problematic ones from the map". Fair privacy call. ## Bits to distance Each bit halves the box your position gets snapped to. The firmware keeps the top N bits of latitude and longitude, then moves the point to the middle of its box, so each coordinate is off by at most half a box. That half-box is the number the apps and the docs show: `radius ≈ 2^(31 − N) × 0.0000001° × 111.32 km` | Bits | Radius | Imperial | As a map report | | --- | --- | --- | --- | | 12 | 5.8 km | 3.6 mi | used as set | | 13 | 2.9 km | 1.8 mi | used as set | | 14 | 1.46 km | 0.9 mi | used as set (the default) | | 15 | 730 m | 0.45 mi (about 2,390 ft) | used as set, the finest allowed | | 16 | 365 m | 0.23 mi | swapped for 14 | | 32 | exact | exact | swapped for 14 | | 0 | off (on a channel) | off | treated as unset, so 14 | Sources: the 12-to-15 check in the firmware's MQTT module, and the precision table in the Meshtastic channel docs, which agrees within rounding. ## The one-bit trap The easy mistake is doing the maths on the whole box, `2^(32 − N)`. Every answer comes out one bit off. Only 15 rounds to half a mile. ## If you are about to try this - **Want the finest dot on the map?** Set the map report to 15, not 32. - **Want off the map?** Turn map reporting off. A precision of 0 there doesn't hide you; it becomes 14. - **Channel precision is a separate knob.** On a private channel, 32 is real. On a channel with a public key, the firmware caps it at 15 anyway. - **Change MQTT settings with the official app or CLI.** A tool that writes the whole MQTT block at once can wipe map report fields it doesn't know about. ## Build it yourself You need a Meshtastic node with MQTT map reporting on, and the official app or Python CLI. Pick 12 to 15 from the table, set it, then check the node's log. An "out of range" warning means your number was swapped for 14. Give this to your AIHelp me set Meshtastic position precision. I want my node on the public MQTT map at about \[distance\], and on my private channel I want \[full precision / a blur of about distance\]. Treat the channel precision and the map report precision as two separate settings. For the map report, only use values from 12 to 15, because current firmware swaps anything else (including 32 and 0) for 14. Work out the radius as half the box, 2^(31 − bits) × 0.0000001° × 111.32 km, and show me the table for 12 to 16. Tell me how to set each one with the official app or Python CLI, and how to confirm in the node log that my map report value wasn't replaced. If you have been bitten by a setting that silently means something else, I would like to hear about it. Filed under [Builds](https://willcurran.com/blog/tag/builds) ![](https://willcurran.com/hs-fs/hubfs/will-curran-brand/will-curran-avatar.jpg?width=64&height=64&name=will-curran-avatar.jpg) Will Curran I spent sixteen years building one company, and I have been in the event industry since 2007. These days I write about the technology I actually use — trucks, radios, home infrastructure, and the tools that survive past the first invoice. [All posts by Will →](https://willcurran.com/blog/author/will-curran) Get the next one by email One email per post. No digest, no sponsors. 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