Signal reference

Cell phone signal strength chart: what your dBm reading means.

Signal bars are a quick summary. dBm and radio quality measurements give you a more useful way to compare rooms, locations and network conditions.

-78 dBmA value closer to zero usually means stronger received power, but signal quality and network load still affect performance.

A practical LTE and 5G signal strength chart

For LTE and many 5G connections, RSRP is one of the most useful power measurements. The ranges below are practical reference points rather than universal pass-or-fail rules. Carriers, frequency bands, devices and environments can behave differently.

RSRP readingGeneral interpretationWhat you may notice
-80 dBm or higherExcellentStrong received power and usually stable radio conditions
-81 to -90 dBmGoodReliable service in many everyday situations
-91 to -100 dBmFairUsable, but indoor obstacles or congestion may become noticeable
-101 to -110 dBmWeakSlower or less stable service is more likely
Below -110 dBmVery weakDrops, fallback to another network or loss of service may occur

Why dBm is more useful than signal bars

Phone manufacturers and carriers decide how measurements become one, two or five bars. That means two phones can show different bars in the same place. A numerical reading is more useful when you repeat the same test on the same device.

The best comparison is a trend: measure near a window, deeper inside the building and outdoors, then pair each reading with a speed test. This shows whether received power actually matches the experience on your connection.

RSRP, RSRQ, SINR and RSSI are not the same

RSRP describes the power of LTE or 5G reference signals. RSRQ adds a view of quality and interference. SINR compares the desired signal with interference and noise. RSSI is a broader received-power measurement that can include unwanted energy as well as the serving signal.

A strong RSRP with poor RSRQ or SINR can explain why a phone shows good coverage but delivers an inconsistent connection. No single number tells the entire story.

  • Use RSRP to compare received signal power.
  • Use RSRQ or SINR to understand quality and interference when available.
  • Use download, upload and ping tests to measure the result users actually feel.
  • Repeat measurements at the same time and location before drawing a conclusion.
Keep in context. Do not compare dBm from different measurement types as if they were identical. A -85 dBm RSRP value and a -85 dBm RSSI value describe different things.

Frequently asked questions

Is -90 dBm a good cell signal?

Around -90 dBm RSRP is generally a good, usable reading. Network quality, congestion and the radio band can still change real-world speed.

Is a dBm value closer to zero better?

For received signal power, a value closer to zero is generally stronger. For example, -80 dBm is stronger than -105 dBm.

Why do I have strong signal but slow data?

Strong received power does not rule out congestion, interference, limited spectrum, slow backhaul, throttling or a device configuration problem.

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