A weak Wi-Fi signal is one of the most common causes of unstable internet, but not all users know how to measure it correctly. Indicators like "3 out of 5 bars" on a smartphone or "excellent" status in Windows only provide a rough idea of connection quality. In reality, for accurate diagnosis, you need to work with decibels-milliwatts (dBm) — a unit of measurement that shows the actual signal strength, not the subjective assessment of the device.
In this article, you'll learn how to measure your Wi-Fi router's signal strength on various devices—from smartphones to professional network analyzers. We'll explore what dBm values are considered normal, how to decipher percentage readings, and why even a "full" signal on a laptop can indicate problems. You'll also learn how to distinguish between signal level (how loudly the router "screams") from connection quality (how well your device “hears” this signal).
What is the difference between signal strength and Wi-Fi speed?
Many people are confused signal level (radio wave strength) and connection speed (network bandwidth). These are different things:
- 📶 Signal level (measured in dBm or %) shows how strongly your device "receives" the radio wave from the router. The closer the value is to
0 dBm, the stronger the signal. For example,-30 dBm- Great,-70 dBm- weak. - 🚀 Wi-Fi speed (measured in Mbps) depends on the network standard (for example, Wi-Fi 5 or Wi-Fi 6), channel load, interference, and even how many devices are connected to the router.
Weak signal Maybe reduce the speed, but not always. For example, if the router is giving out -60 dBm (average level), but works on a free channel without interference, the speed will be high. But with -40 dBm (strong signal), but in conditions of strong interference from neighboring networks, the speed may drop.
⚠️ Attention: Router manufacturers often indicate the “transmission power” in their specifications (for example, 20 dBm or 100 mW). This There is no signal strength on your device., and the maximum radiation power of the router itself. The actual level on a phone or laptop will be lower due to distance, obstacles, and interference.
To understand whether the signal is interfering with your internet, you need to:
- Measure the signal level in dBm (and not as a percentage!).
- Compare it with the norm (see table below).
- Check speed on different devices in one place.
Wi-Fi signal strength standards: what do dBm and percentages mean?
Wi-Fi signal strength is measured in decibels-milliwatts (dBm) — logarithmic unit, where 0 dBm = 1 mW of power. Than less the number is absolute (i.e. closer to zero), the stronger signal. For example, -30 dBm better than -70 dBm.
| Signal level (dBm) | Percentage (approximately) | Connection quality | Recommendations |
|---|---|---|---|
-30…-50 dBm |
90–100% | Excellent | Ideal signal for stable operation. Suitable for online gaming and 4K streaming. |
-50…-60 dBm |
70–90% | Good | Suitable for most tasks, but occasional slowdowns are possible under high load. |
-60…-70 dBm |
50–70% | Average | It's sufficient for surfing and HD video, but unstable for online gaming. Moving closer to the router is recommended. |
-70…-80 dBm |
30–50% | Weak | Connection drops and low speeds are possible. A repeater or channel change is required. |
-80 dBm and below |
0–30% | Critical | The network may connect, but it won't work. A signal booster or router replacement is required. |
Percentages on devices (e.g. "signal 75%" in Windows) are subjective assessment, which depends on the Wi-Fi chipset manufacturer. For example, Intel And Qualcomm may show different percentages at the same level dBm. Therefore, for an accurate diagnosis, always rely on dBm.
Critical Information: If your device shows signal strength as a percentage but does not display dBm, use the formula for an approximate conversion: Level (dBm) ≈ -100 + (Percent × 0.7). For example, 60% ≈ -100 + (60 × 0.7) = -58 dBm.
How to Measure Wi-Fi Signal Strength on a Smartphone (Android and iOS)
Smartphones are the most accessible way to check your signal, but not all apps provide accurate data. Let's look at reliable methods for Android And iPhone.
📱 Android: Apps and Hidden Settings
On most phones with Android signal level in dBm can be seen without third-party programs:
- Open
Settings → Wi-Fi. - Connect to your network.
- Click on the network name →
Network management(orAdditionally). - Scroll down to the item
Signal levelorSignal(sometimes hidden inTechnical information).
If it is not in the settings dBm, use applications:
- 🔍 WiFi Analyzer (from farproc) - shows the signal level, channels and interference.
- 📊 NetSpot — creates a heat map of the signal throughout the house.
- 🛠️ WiFi Signal Meter — outputs dBm, RSSI and real-time speed.
⚠️ Attention: On some phones (eg. Xiaomi or Samsung with shell One UI) apps can only show signal strength for networks you are connected to. not connectedTo work around this, temporarily connect to a different network or use airplane mode.
🍎 iPhone: Bypassing Apple's Restrictions
On iPhone And iPad Apple is hiding dBm in the standard settings, but there are workarounds:
- Install the application AirPort Utility (official from Apple).
- Turn on
Wi-Fi scanner modein the application settings (instructions below). - Run the scan and it will show RSSI (analogue dBm) for all networks.
Step-by-step instructions for enabling scanner mode:
Settings → AirPort Utility → the "i" icon in the upper-right corner → turn on "Wi-Fi Scanner"Alternative applications for iOS:
- 📶 WiFi SweetSpots — shows the signal level and recommends the best location for the router.
- 📈 Fing - analyzes the network and displays RSSI in the connection details.
Disable VPN|Turn off Bluetooth (may cause interference)|Close background apps|Put your phone in airplane mode for 10 seconds and turn it back on-->
Measuring signal on Windows 10/11 without software
Windows has built-in tools for checking signal strength, but they are hidden deep within system utilities. The easiest way is to use command line or PowerShell.
🖥️ Method 1: Command Prompt (netsh)
Open Command line as administrator and enter:
netsh wlan show interfacesFind the line in the results Signal — there will be a percentage level. To see dBm, use this command:
netsh wlan show networks mode=bssidIn the output, look for the column Signal with values of type 95% or -45 dBm. If dBm No, it means your Wi-Fi adapter does not support the output of this parameter.
📊 Method 2: Task Manager
A quick but less accurate method:
- Click
Ctrl + Shift + Escto open Task Manager. - Go to the tab
Performance → Wi-Fi. - There will be a graph in the lower right corner
Signal levelin percent.
The downside of this method is the lack of dBm, therefore it is suitable for diagnostics only as an additional tool.
⚠️ Attention: On laptops with adapters Intel (For example, AX200 or AX210) the command line can show Signal in percentages, but hide dBmIn this case, use third-party utilities like inSSIDer or Acrylic Wi-Fi.
Advanced Diagnostics: Wi-Fi Analysis Software
If you need to do more than just measure the signal level, but also analyze interference, select the best channel, or create a heat map of coverage, you'll need specialized programs. They show dBm, noise, channel blocking and other parameters not available in standard tools.
🌍 Free utilities for Windows/macOS
- 📡 inSSIDer (from MetaGeek) — shows all nearby networks, their channels, power, and interference. There's a free version with limitations.
- 🔍 Acrylic Wi-Fi - detailed analysis of networks, including MAC addresses access points and encryption types.
- 📊 NetSpot — creates a heat map of the signal (you need to walk around the house with a laptop to take measurements at different points).
- 🛠️ WiFi Explorer (For macOS) - analogue inSSIDer with standard support Wi-Fi 6.
📱 Mobile apps for deep analysis
- 📶 WiFi Analyzer (farproc) — shows signal graphs, channels and recommends optimal settings.
- 📈 Network Analyzer — tests speed, ping and signal strength in one interface.
- 🔧 WiFi Monitor — outputs RSSI, noise and signal-to-noise ratio (SNR).
Example of output in inSSIDer:
SSID: MyWiFi
BSSID: AA:BB:CC:DD:EE:FF
Channel: 6 (2.4 GHz)
RSSI: -58 dBm
Noise: -92 dBm
SNR: 34 dB
Here it is important to pay attention to:
RSSI— signal level (dBm).Noise— noise level (the lower the better).SNR— signal-to-noise ratio (optimal >25 dB).
What is SNR and why is it more important than just dBm?
SNR (Signal-to-Noise Ratio) shows how much cleaner your router's signal is than the background noise. For example, RSSI = -60 dBm And Noise = -90 dBm SNR will be 30 dB - this is an excellent indicator. But if Noise = -70 dBm, then the SNR will drop to 10 dB, and the connection will be unstable, even if it seems normal RSSI.
How to measure signal strength directly on a router
If you need to know what signal radiates This can be done through the router's web interface (not the one that reaches the devices). However, not all models provide this information—manufacturers often hide the actual transmission power.
📡 Checking via the router's web interface
Instructions for most routers (TP-Link, ASUS, Keenetic, MikroTik):
- Connect to the router via cable or Wi-Fi.
- Open your browser and enter the router's IP address (usually
192.168.0.1,192.168.1.1or192.168.8.1). - Log in (default logins:
admin/adminor see the router sticker). - Go to the section
Wireless network(orWireless). - Find the items
Transmission power(Transmit Power) orWireless network status.
Examples of paths for popular brands:
- TP-Link:
Advanced → Wireless → Wireless Statistics. - ASUS:
Wireless → Professional → Tx Power. - Keenetic:
Wi-Fi network → Access point → Signal level.
In some routers (for example, MikroTik) the transmission power is indicated in dBm, but more often it is given as a percentage (for example, 100% = maximum power permitted by law). In Russia and Europe, this is usually 20 dBm (100 mW) for 2.4 GHz And 30 dBm (1 W) for 5 GHz.
⚠️ Attention: If you see the option in your router settingsTransmit Powerwith meaningHigh/Medium/Low, This not signal level, and adjusting the transmit power. Reducing this setting can reduce interference with neighboring networks, but it will also weaken your signal.
🛠️ Professional Tools: Wi-Fi Analyzers
To accurately measure the router's transmit power, specialized equipment is used:
- 📡 Wi-Fi analyzers (For example, Fluke Networks AirCheck or Ekahau Sidekick) - show the actual radiation power, interference and coverage.
- 📊 Spectrum analyzers (For example, Keysight N9912A) - analyze the radio channel at the physical level.
These devices are expensive (starting at 50,000 rubles) and are used primarily by IT professionals to set up corporate networks. For home use, software solutions are sufficient.
Common Mistakes When Measuring Wi-Fi Signal
Even experienced users sometimes make mistakes that distort measurement results. Here are the most common ones:
- 📱 Measuring the signal near the router. A meter from the router the level will always be excellent (
-30…-40 dBm), but this will not show the real situation in other rooms. Right: Measure in areas of active use (for example, near a sofa or desk). - 🔋 Testing on a discharged deviceWhen the battery charge is low, smartphones and laptops can artificially limit the power of the Wi-Fi module to save energy. Right: Charge the device to 50% or connect it to the network.
- 🌡️ Ignoring temperatureWi-Fi modules reduce performance when overheated. If your laptop or router is hot, the signal strength may be weaker than expected. Right: Allow the devices to cool before taking measurements.
- 📶 Measurements on one device only. Different chipsets (for example, Intel AX200 vs Broadcom BCM4360) “catch” the signal in different ways. Right: Check on 2-3 devices for objectivity.
- 🔄 Failure to take into account interferenceThe signal may be strong (
-50 dBm), but if the channel is loaded with neighboring networks, the speed will be low. Right: use analyzers like inSSIDerto check the channel load.
Another typical mistake is comparison of dBm and percentages between different devices. For example, 70% on iPhone may correspond -60 dBm, and on Android to the same -60 dBm will 85%Always focus on dBm!
FAQ: Answers to Frequently Asked Questions
🔍 Why does my phone have three Wi-Fi bars, but the internet isn't working?
The stripes display signal level, but not connection qualityPossible reasons:
- The router does not distribute the Internet (problems with the provider or in the settings)
WAN). - IP conflict (two devices on the network have the same IP).
- Blocking by
MAC addressin the router settings. - Too much interference on the channel (check in WiFi Analyzer).
What to do: Restart your router, check if the internet works on other devices, and change the Wi-Fi channel in the router settings.
📶 What is the minimum signal strength required for stable internet?
Depends on the task:
- Surfing, social networks:
-70 dBmand above. - HD video (YouTube, Netflix):
-65 dBmand above. - Online games:
-60 dBmand higher (not only the signal is important, but alsoping). - 4K Streaming:
-55 dBmand above.
If the signal is weaker, interruptions are possible, especially under high load.
🛠️ Is it possible to increase the router signal strength?
Yes, there are several ways:
- Place the router in the center of the house/apartment, away from walls and metal objects.
- Change your Wi-Fi channel to a less busy one (use inSSIDer for analysis).
- Update your router firmware (sometimes manufacturers improve signal transmission algorithms).
- Buy repeater (signal amplifier) or Mesh system for a big house.
- Replace your router's antennas with more powerful ones (if they are removable).
It is not recommended to increase the transmission power (Tx Power) in the router settings above the standard values - this may violate the law (in Russia, the maximum permitted power for 2.4 GHz — 100 mW or 20 dBm).
📱 Why does the signal on Android show -40 dBm, but on iPhone it shows -65 dBm in the same place?
This is normal! The difference occurs because:
- Different Wi-Fi chipsets (eg. Qualcomm vs Broadcom).
- Different sensitivity of antennas (at iPhone antennas are often smaller than those of Android smartphones).
- Different measurement algorithms (Apple may artificially lower the readings to save battery).
Focus on connection stability, and not on absolute values. If the internet is working well, the difference in dBm not critical.
🔧 How to check the Wi-Fi signal on a MacBook?
On macOS there is a built-in tool Wireless Diagnostics:
- Clamp
Option (Alt)and click on the Wi-Fi icon in the menu bar. - Select
Open Wireless Diagnostics. - In the window that opens, click
Window → Utilities. - Turn on
Wi-Fi Scan— the program will show all the networks, their RSSI (analogue dBm) and channels.
You can also use Terminal with the team:
/System/Library/PrivateFrameworks/Apple80211.framework/Versions/Current/Resources/airport -sIn the output column RSSI - this is the signal level in dBm.