What is WiFi Signal Strength?


What is Wifi Signal Strength?  It’s been 21 years since wifi technology was introduced. Wifi is a family of radio technologies commonly used for wireless local area networks (WLAN). The technology has revolutionized smart devices and made the fast transmissions possible. Whatever the impact it has made, we can’t deny it.

Understanding radio technology is simple and requires one to get familiar with radio physics terms. Coming to the topic, if we talk about wifi signal strength, it involves some in-depth research. No worries about that complexity, we’ll explain wifi signal strength in a way an average person can understand:

Understanding Wifi Signal Strength – Explained

Signal Strength:

Signal strength is defined as the radio waves’ strength to move around and make data transfer possible. Both the quality and response time contribute to signal strength. The more quality signals are captured with a good response time within the coverage area, the stronger a signal is.

This is what signal strength is all about. In Wifi, we’ve got signals but their strength not only depends on the wifi bars you’re getting on your desktop or mobile. It depends on the router and the number of customers connected to it, too.

Wifi Signal Strength Measurement Unit(s):

  • milliwatts – mW
  • RSSI – Received Signal Strength Indicator
  • dBm – decibels relative to a milliwatt

WiFi Signal Strength has got several units for its measurement.


The most accurate way to express the strength of wireless signals is milliwatts (mW).  However, it is not used in general. The reason is that it ends up with tons of decimal places due to wifi’s extra-low transmit power, which makes it difficult to read and analyze. Although it is the most accurate calculation available difficulty to read makes it a bad choice.


There’s another unit called RSSI (Received Signal Strength Indicator) which is a better solution for strength measurement than mW. The only case with RSSI is that wifi device vendors handle it according to their choice as there are no general standards to follow. Some adapters have a scale of 0-255 while others do measurements in 0-60.

After knowing about the demerits of milliwatts and RSSI, there must be a standard measuring unit that is accepted globally?


The most convenient and standardized way to express signal strength comes out to be dBm (decibels relative to a milliwatt). With its convenience, vendors have started to use dBm in their product specifications.

Unlike mW, dBm has no decimal values involved. It just ranges from -30 to -100, which makes it quite readable.

How to measure WiFi Signal Strength using dBm

dBm deals in negative values and we have an idea that lower negative value is higher than higher negative value.

Explaining it with an example: -20dBm is higher than -50dbm.

Next, about measurement, the unit doesn’t offer values in linear form. Being a logarithmic standard, the signal changes measured are not gradual or smooth.

There’s a rule of 3s and 10s to highlight the measurement nature of dBm:

  • 3dB of loss = -3 dB = half of the standard signal strength
  • 3dB of gain = +3 dB = means double signal strength
  • 10 dB of loss = -10 dB = 10 times lower strength
  • 10 dB of gain = +10 dB = 10 times more signal strength

If you use a free app like “WiFi Analyzer” on your smartphone, you will be able to see your WiFi signal strength.

What’s the Ideal WiFi Signal Strength?

Now, since we’ve gone through the standard measuring unit and its mechanics, let’s talk about ideal signal strength.

Ideal signal strength varies according to your use. If you’re using the internet for general purposes like sending emails, scanning barcodes, or browsing the web, -70dBm is adequate WiFi signal strength.

Contrary to it, if you use your internet for video streaming or video calls, where more data is consumed instantly, -67 dBm or less becomes the ideal strength.

In this way, ideal signal strength depends on your internet requirements. If you’re a heavy user like you consume more data in less time (torrenting/downloading/streaming), you require more signal strength (less in value as dBm is measured in negative). So you can’t predict an ideal signal strength without looking at one’s internet consumption rate.

Factors Affecting Signal StrengthWiFi Signal Strength Measured

Signal strength is affected through several factors that involve the environment and the devices set up.

Strength varies depending on various areas within the network itself from the technology of adapters to the environment through which signals will travel. No doubt, we can’t deny the fundamentals laws of physics when signals are a part of the discussion. Some factors can be avoided or their effect can be minimized either through adapter upgrade or better network planning. While some factors can’t be avoided, so a replacement is used to minimize them.

Here are some of the common factors that affect wifi signal strength:

#1. Physical Obstructions

Wireless signals are not that strong to penetrate through solid objects which may include walls, buildings, hills or even people. The more hindrances are there in between the transmitter and receiver, the more you’ll experience a negative slope for signal strength. Keeping a clear path for signals to travel eventually enhances the signal’s strength.

In the digital age, we’ve got enough techniques to make signals travel smoother. One way is to use a piece of equipment that transmits signals of low frequency. Low-frequency signals have better penetration power so they travel through most of the surfaces even through solid ones.

Another way to minimize the effect of physical obstructions is to use high-frequency signals as they have the best reflecting power. So in some scenarios, reflecting a signal to make sure it reaches the receiver works better than sending it through objects.

#2. Network Range & Distance between Devices

This is the most common factor which affects wifi signal strength. The equipment or network adapter you’re using is responsible for network range. The better the equipment, the stronger signals it transmits. On the other hand, if you have low quality or outdated devices, network range can’t meet the strength requirements.

Distance between transmitter and receiver is another thing to consider. Mathematically, strength is inversely proportional to the distance by three times. In simple words, the greater the distance lower the strength. This is how it works!

#3. Signal Sharing

Whether it is a mobile hotspot or a network adapter, you can connect to multiple devices at one time. When there are multiple devices connected, signals are shared and data transfers occur simultaneously. This instantaneous transmission of signals to multiple devices surely affects signal strength. That’s natural and it doesn’t have a solution other than using the latest hardware-backed equipment. Make sure your device is full-duplex so that it can transmit and receive signals to several devices simultaneously with minimum strength reduction.

#4. Poorly Deployed Antennas

This happens only when you’ve no idea about placing antennas around for better signals distribution. In case if antennas are deployed poorly, you’ll experience issues towards signal strength. Antennas are responsible for transmitting signals in a specific direction or orientation, hence a better deployment for antennas will surely benefit signal strength.

Depending on the device placement, you can choose sector antennas that are limited to one direction only or go with omnidirectional antennas that transmit signals in multidirectional. The later ones are great for an office environment where devices are located in almost all directions.

#5. Wireless Network Interference

As it involves radio-physics, interference of signals can happen. Wireless networking is getting common day by day due to its convenience. Now, several networks operate at a single frequency simultaneously. This may cause signal interference which eventually reduces the signal’s strength to reach the connected device effectively.

Other than WiFi connections, wireless technologies like your phone or microwave ovens can also cause hindrance in the wifi signal’s path. There’s no solution to minimize it other than using high-quality equipment or the latest technologies.

WiFi Signal Strength Test – How to Measure?

Measuring signals strength requires a few clicks to continue. No additional apps are required to measure strength when you’re using a desktop.

For mac OS, press and hold the Alt key while clicking the WiFi icon on the status bar. A list of networks will appear, find the connection you’re connected to and a graph showing the signal’s strength will appear.

In the same way for Windows, you can find the wireless signal’s strength as you open wireless properties in network settings right from the control panel.


WiFi signal strength can be measured easily from built-in apps. On top of the scale, we’ve got dBm as the standard unit as every vendor makes the same use of it. Strength ranges within -30dBm / -100dBm. The lesser value we’ve in dBm (due to its sign) stands for better strength and signals transmission. This is how Wifi signal strength is identified and measured!WiFi