How the Meshtastic Signal Meter Works
The Meshtastic signal meter — the familiar bars or status color in the app — is calculated very differently than the "bars" on a traditional cell phone or WiFi router.
Most consumer devices simply measure how "loud" a signal is. However, because Meshtastic uses LoRaLoRaA low-power, long-range wireless communication technology used by Meshtastic devices to enable communication over distances of several kilometers without the need for cellular, Wi-Fi, or other traditional network infrastructures. (Long Range) technology, its signal meter measures how clear the signal is, relative to the specific settings your mesh is using.
1. The Two Metrics: "Loudness" vs. "Clarity"
Every time the LoRaLoRaA low-power, long-range wireless communication technology used by Meshtastic devices to enable communication over distances of several kilometers without the need for cellular, Wi-Fi, or other traditional network infrastructures. radio chip receives a message, it reports two measurements:
- RSSIRSSI (Received Signal Strength Indicator). The raw power level of a received signal, where a value closer to zero is stronger. Clients rate signal quality from SNR rather than RSSI. (Received Signal Strength Indicator): The loudness of the raw power hitting your antenna.
- SNRSNR (Signal-to-Noise Ratio). A measure used in communications to quantify the level of a desired signal to the level of background noise. In Meshtastic and other wireless systems, a higher SNR indicates a clearer signal that can enhance the reliability and quality of data transmission. (Signal-to-Noise RatioSNR (Signal-to-Noise Ratio). A measure used in communications to quantify the level of a desired signal to the level of background noise. In Meshtastic and other wireless systems, a higher SNR indicates a clearer signal that can enhance the reliability and quality of data transmission.): The clarity of the signal compared to the background static.
💡 Tip: Here's an analogy — imagine you are trying to hear a friend talking to you.
- RSSIRSSI (Received Signal Strength Indicator). The raw power level of a received signal, where a value closer to zero is stronger. Clients rate signal quality from SNR rather than RSSI. is how loud their voice is.
- The Noise Floor is the background noise in the room (air conditioning, other people talking, traffic).
- SNRSNR (Signal-to-Noise Ratio). A measure used in communications to quantify the level of a desired signal to the level of background noise. In Meshtastic and other wireless systems, a higher SNR indicates a clearer signal that can enhance the reliability and quality of data transmission. is how easily you can distinguish your friend's voice from the background noise.
If your friend shouts at you at a deafening rock concert, the signal is incredibly loud (High RSSIRSSI (Received Signal Strength Indicator). The raw power level of a received signal, where a value closer to zero is stronger. Clients rate signal quality from SNR rather than RSSI.), but you still can't understand them because the background noise is louder (Bad SNRSNR (Signal-to-Noise Ratio). A measure used in communications to quantify the level of a desired signal to the level of background noise. In Meshtastic and other wireless systems, a higher SNR indicates a clearer signal that can enhance the reliability and quality of data transmission.). Conversely, if your friend whispers to you in a dead-silent library, the signal is very weak (Low RSSIRSSI (Received Signal Strength Indicator). The raw power level of a received signal, where a value closer to zero is stronger. Clients rate signal quality from SNR rather than RSSI.), but you can understand them perfectly (Great SNRSNR (Signal-to-Noise Ratio). A measure used in communications to quantify the level of a desired signal to the level of background noise. In Meshtastic and other wireless systems, a higher SNR indicates a clearer signal that can enhance the reliability and quality of data transmission.).
2. The Magic of LoRa: Hearing "Below the Noise Floor"
For standard radios (like FM or WiFi), if the background noise is louder than the signal (a negative SNRSNR (Signal-to-Noise Ratio). A measure used in communications to quantify the level of a desired signal to the level of background noise. In Meshtastic and other wireless systems, a higher SNR indicates a clearer signal that can enhance the reliability and quality of data transmission.), the receiver just hears static.
LoRaLoRaA low-power, long-range wireless communication technology used by Meshtastic devices to enable communication over distances of several kilometers without the need for cellular, Wi-Fi, or other traditional network infrastructures. is special. It uses "Spread Spectrum" modulation, which allows the radio to mathematically pull a signal out of the air even when it is buried deep underneath the background noise. This is why you will frequently see negative SNRSNR (Signal-to-Noise Ratio). A measure used in communications to quantify the level of a desired signal to the level of background noise. In Meshtastic and other wireless systems, a higher SNR indicates a clearer signal that can enhance the reliability and quality of data transmission. numbers in Meshtastic (e.g., -10 dB, which means the signal is 10 decibels weaker than the background static).
Depending on which Meshtastic preset you are using (e.g., LongFast vs. ShortFast), the radio has a specific SNRSNR (Signal-to-Noise Ratio). A measure used in communications to quantify the level of a desired signal to the level of background noise. In Meshtastic and other wireless systems, a higher SNR indicates a clearer signal that can enhance the reliability and quality of data transmission. Limit — the absolute maximum amount of noise it can tolerate before the message is completely lost to the static.
3. How the Signal Meter Calculates Quality
The app rates your signal quality (None, Bad, Fair, or Good) from SNRSNR (Signal-to-Noise Ratio). A measure used in communications to quantify the level of a desired signal to the level of background noise. In Meshtastic and other wireless systems, a higher SNR indicates a clearer signal that can enhance the reliability and quality of data transmission. alone, measured relative to the preset's SNRSNR (Signal-to-Noise Ratio). A measure used in communications to quantify the level of a desired signal to the level of background noise. In Meshtastic and other wireless systems, a higher SNR indicates a clearer signal that can enhance the reliability and quality of data transmission. Limit — the demodulation floor described above. It deliberately does not factor RSSIRSSI (Received Signal Strength Indicator). The raw power level of a received signal, where a value closer to zero is stronger. Clients rate signal quality from SNR rather than RSSI. into the rating: without the local noise floor, RSSIRSSI (Received Signal Strength Indicator). The raw power level of a received signal, where a value closer to zero is stronger. Clients rate signal quality from SNR rather than RSSI. cannot tell you whether a signal is actually decodable, so SNRSNR (Signal-to-Noise Ratio). A measure used in communications to quantify the level of a desired signal to the level of background noise. In Meshtastic and other wireless systems, a higher SNR indicates a clearer signal that can enhance the reliability and quality of data transmission.-versus-the-preset-limit is the meaningful measure. (RSSIRSSI (Received Signal Strength Indicator). The raw power level of a received signal, where a value closer to zero is stronger. Clients rate signal quality from SNR rather than RSSI. is still displayed to you elsewhere.)
Because the rating is relative to the preset limit, the same SNRSNR (Signal-to-Noise Ratio). A measure used in communications to quantify the level of a desired signal to the level of background noise. In Meshtastic and other wireless systems, a higher SNR indicates a clearer signal that can enhance the reliability and quality of data transmission. can rate differently on different presets — -15 dB is healthy on LongSlow but unusable on ShortFast. Letting limit be the active preset's SNRSNR (Signal-to-Noise Ratio). A measure used in communications to quantify the level of a desired signal to the level of background noise. In Meshtastic and other wireless systems, a higher SNR indicates a clearer signal that can enhance the reliability and quality of data transmission. Limit, here is how the app picks the bars (or color):
| Level | Bars | Criteria | Meaning |
|---|---|---|---|
| Good | 3 | SNRSNR (Signal-to-Noise Ratio). A measure used in communications to quantify the level of a desired signal to the level of background noise. In Meshtastic and other wireless systems, a higher SNR indicates a clearer signal that can enhance the reliability and quality of data transmission. above the preset's limit | Signal is comfortably above the demodulation floor — healthy connection. |
| Fair | 2 | less than 5.5 dB below the limit | Decodable, but getting close to the floor. |
| Bad | 1 | 5.5 dB to 7.5 dB below the limit | At the very edge of what the preset can recover. |
| None | 0 | more than 7.5 dB below the limit | Below the floor — transmission lost to noise. |
Note: The fixed SNRSNR (Signal-to-Noise Ratio). A measure used in communications to quantify the level of a desired signal to the level of background noise. In Meshtastic and other wireless systems, a higher SNR indicates a clearer signal that can enhance the reliability and quality of data transmission. thresholds you may have seen elsewhere (
-7 dB/-15 dB) are now only used for coloring individual hops in traceroute results — not for the per-node signal meter described here.
4. What This Means for You
Because Meshtastic's meter acts as a "Clarity Meter", it behaves differently than what most people expect:
💡 Tip: Don't panic over low RSSIRSSI (Received Signal Strength Indicator). The raw power level of a received signal, where a value closer to zero is stronger. Clients rate signal quality from SNR rather than RSSI.. You might see a seemingly terrible RSSIRSSI (Received Signal Strength Indicator). The raw power level of a received signal, where a value closer to zero is stronger. Clients rate signal quality from SNR rather than RSSI. value like
-118 dBm. On a cell phone, you would have zero bars. But if you have an SNRSNR (Signal-to-Noise Ratio). A measure used in communications to quantify the level of a desired signal to the level of background noise. In Meshtastic and other wireless systems, a higher SNR indicates a clearer signal that can enhance the reliability and quality of data transmission. of+2 dB, Meshtastic will still show a strong signal! The library is quiet, so the whisper is heard perfectly.
⚠️ Warning: Watch out for local noise. If you hook up a massive antenna and see a great RSSIRSSI (Received Signal Strength Indicator). The raw power level of a received signal, where a value closer to zero is stronger. Clients rate signal quality from SNR rather than RSSI. (e.g.,
-90 dBm) but your signal meter is only showing 1 Bar (Bad), you have a problem. It means you have local interference — perhaps a cheap power supply, a noisy computer, or a nearby radio tower — creating so much static that it is drowning out your mesh.
Where Signal Information Appears
In the app, signal data is shown in several places:
- Node list — signal bars icon next to each node
- Node detail — SNRSNR (Signal-to-Noise Ratio). A measure used in communications to quantify the level of a desired signal to the level of background noise. In Meshtastic and other wireless systems, a higher SNR indicates a clearer signal that can enhance the reliability and quality of data transmission., RSSIRSSI (Received Signal Strength Indicator). The raw power level of a received signal, where a value closer to zero is stronger. Clients rate signal quality from SNR rather than RSSI., and signal quality in the device metrics section
- Traceroute — per-hop signal quality for each relay node
- Signal metrics — historical SNRSNR (Signal-to-Noise Ratio). A measure used in communications to quantify the level of a desired signal to the level of background noise. In Meshtastic and other wireless systems, a higher SNR indicates a clearer signal that can enhance the reliability and quality of data transmission. and RSSIRSSI (Received Signal Strength Indicator). The raw power level of a received signal, where a value closer to zero is stronger. Clients rate signal quality from SNR rather than RSSI. data in the metrics charts
Related Topics
- Nodes — where signal bars appear in the node list
- Node Metrics — SNRSNR (Signal-to-Noise Ratio). A measure used in communications to quantify the level of a desired signal to the level of background noise. In Meshtastic and other wireless systems, a higher SNR indicates a clearer signal that can enhance the reliability and quality of data transmission./RSSIRSSI (Received Signal Strength Indicator). The raw power level of a received signal, where a value closer to zero is stronger. Clients rate signal quality from SNR rather than RSSI. history and the per-node signal quality reference
- Settings — Radio & User — modem presets and their SNRSNR (Signal-to-Noise Ratio). A measure used in communications to quantify the level of a desired signal to the level of background noise. In Meshtastic and other wireless systems, a higher SNR indicates a clearer signal that can enhance the reliability and quality of data transmission. limits