How long a Meshtastic packet sits on the air for each modem preset, and how much of the shared channel a fleet of nodes uses up. Meshtastic adds a 16-byte header and a 16-symbol preamble to every packet; the slower long-range presets pay for their reach in airtime. Meshtastic warns once channel utilization passes 25%.

A rough range estimate for a Meshtastic link from the radio link budget and the line-of-sight horizon. The big lesson: LoRa's link budget is enormous, so real range is almost always limited by terrain and antenna height, not transmit power. Raising an antenna a few metres helps far more than a few more dBm.

How far a message can travel across a Meshtastic mesh, given the hop limit and a typical single-hop range. Each hop lets the message be rebroadcast one node further out — but every hop also adds latency and channel traffic, so Meshtastic caps the hop limit at 7 (default 3). More hops is not always better.

Build a shareable Meshtastic channel URL from a name, key, modem preset and region — the same meshtastic.org/e/#… link the app generates, ready to paste or scan as a QR. Or paste an existing channel URL to decode it back to readable settings. Everything is built in your browser.

Check whether a message fits in a single Meshtastic packet. The data payload is capped at 237 bytes; on the air each packet also carries a 16-byte header. Type a message to see its byte size, how much of the packet it fills, and the time on air for your modem preset. Emoji and accented characters take several bytes each in UTF-8.

The frequency band, maximum transmit power and duty-cycle rules Meshtastic uses for each region. You must set the region that matches where you are — it is a legal requirement, and nodes on different regions cannot hear each other. Pick yours to highlight it; figures are a guide, always confirm your national regulations.