A weak Wi-Fi signal can cause slow downloads, buffering, interrupted video calls and frequent disconnections. You can measure Wi-Fi signal strength using your phone, computer or router application. If the signal is weak, moving the router, changing the frequency band, reducing interference or installing a mesh system can improve coverage.
What Is Wi-Fi Signal Strength?
Wi-Fi signal strength measures how reliably your router’s wireless signal reaches a connected device. It is influenced by the distance from the router, walls, furniture, electronic interference and the frequency band being used.
Most phones and computers display Wi-Fi strength as curved bars. These bars provide a quick estimate, but they are not precise enough for comparing rooms or router positions.
For a more accurate measurement, check the signal in decibel-milliwatts, commonly written as dBm.
How Is Wi-Fi Signal Strength Measured?
Wi-Fi signal strength normally appears as a negative dBm number. A number closer to zero indicates a stronger signal.
For example, -45 dBm is substantially stronger than -75 dBm.
| Signal strength | Connection quality |
| -30 to -50 dBm | Excellent |
| -51 to -60 dBm | Very good |
| -61 to -67 dBm | Good |
| -68 to -70 dBm | Usable |
| -71 to -80 dBm | Weak |
| Below -80 dBm | Very weak or unstable |
A signal around -50 dBm is suitable for demanding activities. Around -67 dBm is generally sufficient for browsing, streaming and video calls. Once the signal drops below approximately -75 dBm, performance may become inconsistent.
These values should be treated as practical guidelines rather than guarantees. Network congestion, interference and internet speed can still affect performance even when the Wi-Fi signal is strong.
Wi-Fi Signal Strength vs Internet Speed
Wi-Fi signal strength and internet speed are related, but they are not the same measurement.
Wi-Fi strength measures the wireless connection between your device and router. Internet speed measures how quickly data travels between your network and the internet.
You can therefore experience:
- Strong Wi-Fi but slow internet because of ISP congestion
- Weak Wi-Fi even though you have a fast internet plan
- Good download speed but poor stability because of interference
- Slow speeds because too many devices are using the connection
Test both the Wi-Fi signal and internet speed before deciding whether the router or internet plan is responsible.
How to Measure Wi-Fi Signal Strength on Android
The exact options depend on the phone manufacturer and Android version.
Check the Wi-Fi icon
Stand in the area you want to test and look at the Wi-Fi icon in the status bar. Fewer filled curves generally indicate a weaker connection.
This method is quick but does not provide an exact dBm reading.
Check Android Wi-Fi details
- Open Settings.
- Select Network and internet, Connections or Wi-Fi.
- Tap the connected Wi-Fi network.
- Look for Signal strength, Network quality or a similar option.
Some Android phones show a description such as Excellent, Good or Weak instead of a numerical value.
Use a Wi-Fi analyser application
A reputable Wi-Fi analyser can display:
- Signal strength in dBm
- Nearby wireless networks
- Congested channels
- The frequency band being used
- Changes in signal strength as you move around
Test the same network in several rooms and record the dBm value in each location. Avoid comparing readings from different devices because their antenna performance can differ.
How to Measure Wi-Fi Signal Strength on iPhone
An iPhone displays general signal quality through the Wi-Fi icon, but iOS does not normally show the connected network’s dBm value directly in Wi-Fi settings.
For a more detailed test, you can use Apple’s AirPort Utility:
- Install AirPort Utility from the App Store.
- Open the iPhone Settings application.
- Scroll down and select AirPort Utility.
- Enable Wi-Fi Scanner.
- Open AirPort Utility.
- Select Wi-Fi Scan.
- Set the scan duration and begin scanning.
The RSSI value displayed for a network represents its received signal strength. A value closer to zero is stronger.
Only scan networks you are authorised to use. The feature measures nearby wireless signals; it does not provide access to those networks.
How to Check Wi-Fi Signal Strength on Windows
Use the taskbar icon
Select the Wi-Fi icon on the Windows taskbar. The number of filled bars gives you a general indication of signal quality.
Use Command Prompt
- Open Command Prompt.
- Enter the following command:
netsh wlan show interfaces
- Find the Signal field.
Windows usually presents this value as a percentage rather than dBm. Run the command in different rooms to compare coverage.
A lower percentage in one area suggests that distance, walls or interference are weakening the
