Look around you, most of the smart devices can hook up to the wireless network. It is so convenient to build a WiFi network and connect different types of devices seamlessly without cables. WiFi signal strength depends on multiple factors such as distance from the access point, obstructions in between, type of WiFi router, noise in the form of electrical signals, etc. So, do you know how to measure WiFi signal strength? There are several tools and software available such as InSSIDer, NetSpot, Wireshark, WiFi Analyzer, etc. You can also count the number of WiFi bar on your device.


You might ask why it is essential? It is vital for applications and functions like internet browsing, email, watching online movies, etc. All depend primarily on WiFi signal strength. It does not matter if you have Gbps internet connection. If you are not getting the required WiFi signal, you will not be able to carry out desired activities on a network.

It’s not rocket science, and you can get the knack of WiFi signal strength in a matter of few minutes of a good read. First thing first, let’s understand some basics.

Milliwatts (mW)

WiFi signal does carry some power in a low number. The value can be expressed as milliwatts or mW. But the overall number carries too many zeros after the decimal. So, a good WiFi signal like -10 dBm is equivalent to 0.1 mW, -40dBm is 0.0001 mW and a weak signal like -100 dBm equals to 0.0000000001 mW.

The mW numbers are not convenient to look at first glance. Thus, dBm formats were adopted as they were small numbers.

decibel-milliwatts (dBm)

dBm is a power ratio represented in decibels (dB) with reference to 1 milliwatt (mW). These numbers are expressed on a logarithmic scale, which is capable of expressing bigger and smaller number conveniently in a short form. In a log 10 scale, -4 represents 10 to the power of -4, which equals 0.0001.

Similarly, a negative Decibel-milliwatt (dBm) number represents negative exponent in power calculations. Thus, 0 dBm is equivalent to 1 milliwatt (mW) of power and -20 dBm equals to 0.01 mW.

You can use the mathematical expression for power or dBm calculations. Here x is dBm and P is power in milliwatts (mW).

dBm calculation formula

WiFi signal strength

A stronger WiFi signal means that it can carry more power to the wireless client and ultimately results in better connection and higher network speeds. Also, now you know that -30 dBm (0.001 mW) is more powerful WiFi signal than -60 dBm (0.000001 mW) signal.

Usually, WiFi signal varies in the range of -30 dBm to -90 dBm, where -30 dBm is an ideal scenario with highest possible wireless signal strength and -90 dBm is an almost unusable signal.


Received Signal Strength Indicator (RSSI)

It is an arbitrary and unitless number, which defines power level being received by the wireless networking card after possible cable and antenna loss. A high RSSI number represents a strong signal. The RSSI range typically varies with different manufacturers. For example, Cisco cards follow 0-100 as RSSI range, whereas this range in Atheros cards is 0-127.

You can measure RSSI with the help of network monitoring tools like Wireshark, Inssider, etc.

Noise level

There could be various background noises such as interfering radio frequencies, crosstalk, etc. The noise level is again measured in dBm with the range in between 0 and -120. Here also, -30 dBm is stronger noise level than -60 dBm.

Ultimately, you want low noise signal and hence will desire -120 dBm noise which is not possible in real world.

Signal to noise ratio (SNR)

As the name suggests, SNR is the ratio of signal strength and the noise level. SNR is a positive dBm number. For example, if you are receiving wireless signal strength as -60 dBm and the noise level strength is -70 dBm. Then SNR, in this case, is +10 dBm.

What is a good WiFi signal strength?

You may ask what best WiFi signal strength is? The answer depends on the type of usage. For instance, if you are surfing the internet and reading things, then even average WiFi signal strength will suffice your needs. But if you wish to watch online movies or HD videos on YouTube, then you may have to look for good WiFi signal.

WiFi Signal Range

Connection Type


-30 to -50 dBmExcellent to good signal strengthCan do anything in this range
-50 to -60 dBmGood to average signal strengthHD online video streaming and fast movie downloads, etc.
-60 to -70 dBmFair to poor signal strengthVoIP calls, Non-HD online video streaming, Uninterrupted internet surfing, etc.
-70 to – 90 dBmAverage signal strengthUnreliable connection. You might be able to check a few emails if lucky

How to measure signal strength?

Now that you know all basics related to WiFi signal strength, you are ready to measure it via various options available. We have entailed some comfortable ways to determine the signal strength of your Wi-Fi connection.

However, different approaches may give contradicting results based on variation in sample collection and timing used to average the signal strength.

For Computer & Laptop Users

In Built OS Utility Option

There is an inbuilt utility feature in almost all operating systems to monitor wireless network connections. It’s the quickest and hassle-free way to measure the Wi-Fi strength.


Steps –

Go to Task Bar > Right Click on Wi-Fi Icon> Left Click Network & Sharing Centre> Click on Access Type (Name of Router)>Wi-Fi Status> Speed & Signal Quality (Number of Green Bars)

measure wifi signal strength on macbook

If you have a MacBook, then you are in luck as it has hidden option to check the WiFi signal. Click on WiFi symbol on top bar by keeping Option key on the keyboard. Voila! You will get the following screen with almost every related signal parameters.

Software applications and tools


It is a paid Wi-Fi optimization and troubleshooting software that is an answer to questions like which rooms have good Wi-Fi coverage? Are you on the best channel for good coverage? What other devices are transmitting in my environment, and are they interfering? The software is available for Mac and Windows users.

inssider wifi analyzer software

Post installation you click on Time Graph tab to see the signal strength graphs for all found wireless networks. The display shows signal strength of five minutes period.


NetSpot is a paid WiFi signal strength analyzer. You can generate a heat map of WiFi signal strength by uploading the area map. If you do not have the chart handy, then you can draw a custom one in this software.

netspot software

You can walk in all areas to determine wireless signal, and at the end, heat map will be generated. NetSpot can even detect hidden WiFi networks and display information like channel info, transmit rate, band, security type, and other information. The software is available on Windows and Mac platform.

WiFi Analyzer

WiFi analyzer is a freemium application for Windows users on desktop and mobile platform. The free version will allow you to identify WiFi problems, the best location for your wireless router, etc.

WiFi Analyzer for windows

Pro version has more capabilities such as beeper for signal strength, filters, change signal strength borders, etc.


Wireshark is free software to determine network related issues via data packet analyzer. The tool is suitable for network professionals since novice users might have to read the manual or watch YouTube videos to understand the functionalities of this tool. This software is available on Mac as well as Windows platform.

For Mobile/Tablet Users

Any mobile whether it’s an android, iOS or a tablet has an option under settings to show the available Wi-Fi connections around as well as their strengths.


Go to Settings> Click on Wi-Fi> See the relative strengths of all available networks

You can also use free mobile applications such as WiFi Analyzer on Android and AirPort Utility on iOS platform.

Wi-Fi Locators

Wi-Fi locators are a portable electronic device that detects the presence of any access point in the vicinity of a portable device. The basic functionality is to avoid booting up each time in an attempt to connect on a “hit or miss” scenario.

By 4-6 LEDs installed on the locator, the signal strength is displayed. However, contrary to the above it just predicts the network presence in the vicinity by these LEDs and not the actual strength.

How to measure WiFi signal strength? There are several tools and software available such as InSSIDer, NetSpot, Wireshark, WiFi Analyzer, etc. You can even count the number of WiFi bar on your device. WiFi signal strength depends on multiple factors such as distance from the access point, obstructions