Skip to content

How to know the signal strength on an Android mobile and what the dBM values ​​mean

25 mayo, 2021

Mobile coverage can vary for a lot of factors, and usually the only way you have to be aware of the same is through the signal bars of the status bar, which can be misleading.

If you want to have more precise information about signal strength In an Android mobile, you can see the precise data of dBM and asu from the settings. We will see how to do it and what this data means.

How to view signal strength

Bars Bar measurement is not standard

Seeing the signal strength is as easy as looking at the top of the mobile to see “the streaks” of the signal, although this has a fundamental problem: they are not reliable. There is no standard on what values ​​each bar should represent, so that manufacturers and operators can change what “three bars” mean from one mobile to another, or from one operator to another.

What are LPWA networks, the great parallel channel to 5G for connected devices

A better way to get signal strength is check dBm values (decibel-milliwatt) or ASU (Arbitrary Strength Unit), both available -or at least the decibels- from the phone’s status, in the Android settings.

Network status

The location of this menu may vary slightly in different layers of customization, so if you can’t find it, it is best to use the search engine in the settings. The result of the signal strength will be displayed in two numbers: a negative number in dBm and a positive number in to its.

What is dBm

The dBm figure corresponds to the decibel-milliwatt measurement. It is a logarithmic measure of power in relation to one milliwatt, used in telecommunications to measure signal strength that reaches the mobile from a cellular network.

This digit is always negative, being greater – and therefore better – the closer it is to zero. In 3G and 4G / LTE networks, the meaning of these values ​​varies slightly, although they roughly range from excellent intensity with around -80 dBm to no coverage around -110 dBm.





Without signal


-70 dBm or more

-71 to -85 dBm

-86 to -100 dBm

-101 to -109 dBm

-110 dBm or less

4G / LTE

-90 dBm or more

-91 to -105 dBm

-106 to -110 dBm

-111 to -119 dBm

-120 dBm or less

The interpretation of the figures are not set in stone, but they will help you get an idea of how to interpret the dBm data displayed by your mobile. For example, in the screenshot above we saw -104 dBm on 4G, which would be considered “good” quality, albeit narrowly. The mobile marks it as four lines.

What is asu

Generally, the mobile will also indicate the number asu, acronym for Arbitrary Strength Unit. This unit measures the same, signal intensity, although it does it in a different way. In this case it is proportional to the signal strength measured by the phone.

The value of asu can be calculated from dBm, although the formula changes for GSM, UMTS or LTE networks. By measuring the same, it will generally be easier for you to use dBm as a measure, the use of which is more standardized. In this case the value is positive and the higher it is, the better the signal.

Better – and easier – with apps


Checking the dBm or asu data and remembering the ranges that are good or not is feasible, although it requires you to have a good memory. On the other hand, we have seen that the bars that Android shows at the top are really not very reliable. An easy way to have the best of both worlds is install an app that does the calculation for you and show you the result easily.

There are many apps on Google Play that do this, like Signal Strength or NetWork Signal Information, to name a few. Basically, these apps check dBm and / or asu levels and they show you the result in a graph so you can see the intensity of the signal without having to eat the coconut.

Signal Strength

Signal Strength