Wi-Fi router power of 20 dBm – how much is that in meters? A full breakdown

When you choose a Wi-Fi router or set up a home network, one of the key parameters is transmitter power, which is measured in decibels-milliwatts (dBm). Often in the characteristics of devices there is a value 20 dBm But what does this mean in practice? How many meters does such a router cover in an apartment, house, or office? The answer isn't as simple as it seems: the actual range is affected not only by technical specifications but also by physical obstacles, the signal frequency (2.4 or 5 GHz), and even weather conditions.

In this article we will examine in detail:

• 📡 What is it? 20 dBm in milliwatts and how it relates to other power values.
• 📏 How to calculate the approximate signal range in meters - from simple formulas to real-world tests.
• 🏠 Why will the sound coverage be different in an apartment and outdoors (spoiler: concrete walls "eat up" up to 12 dB!).
• ⚡ What to do if 20 dBm is not enough - from changing the channel to installing a repeater.

You will learn why two routers with the same power can behave differently, how to check the actual coverage in your premises, and what hidden settings will help you get the most out of your existing equipment. No complex theory—only practical advice and verified data.

What is 20 dBm and how do you convert it to milliwatts?

Wi-Fi transmitter power is measured in dBm (decibel milliwatt) is a logarithmic unit that shows the ratio of power to 1 milliwatt. Meaning 20 dBm means that the device is emitting a signal with a power 100 mW (milliwatt). This is the standard value for most mid-range home routers - from TP-Link Archer C6 to ASUS RT-AX55.

For comparison:

• 📱 Smartphone in hotspot mode: usually 10–15 dBm (10–30 mW).
• 🖥️ Office routers (for example, Ubiquiti UniFi): to 27–30 dBm (500–1000 mW).
• ⚡ Professional antennas for outdoor installation: up to 36 dBm (4000 MW).

It is important to understand that increase in power by 3 dBm means doubling Actual power in milliwatts. For example, 23 dBm = 200 mW, and 26 dBm = 400 mW. However, this doesn't mean the signal range will increase proportionally—the laws of physics and the properties of radio wave propagation come into play here.

How does 20 dBm affect Wi-Fi range?

The theoretical signal range depends on many factors, but the basic formula relates the transmitter power (Pt), receiver sensitivity (Pr), signal frequency and attenuation coefficients. Simplified for 2.4 GHz (the most common range) you can use the rule of thumb:

In the open (without obstacles) router with power 20 dBm can provide a stable signal over a distance:

• 📶 80–120 meters at speeds up to 54 Mbps (standard 802.11g).
• 📶 50–80 meters at a speed of 300+ Mbps (standard 802.11n/ac).

However, in real conditions (apartment, office) these figures are reduced in 3-5 times because of:

• 🧱 Walls and partitions (brick weakens the signal on 6–12 dB, concrete - on 15–20 dB).
• 🪟 Glass with a metallic coating (weakening up to 3–5 dB).
• 📡 Interference from other networks (especially in apartment buildings).

Comparison of 20 dBm with other power values

To understand how long 20 dBm will last, let's compare it to other typical values. Below is a table with the approximate range in open areas (2.4 GHz, standard 802.11n):

Please note: doubling the power (from 20 to 23 dBm) gives an increase in range of only 20–25% outdoors and even less indoors. This is due to logarithmic nature of attenuation signal - the further you are from the router, the more weakened each additional "step" of power is.

⚠️ Please note: In some countries (for example, in the EU), the maximum power of Wi-Fi transmitters is legally limited to 20 dBm (100 mW) For the 2.4 GHz band. Exceeding this value may require certification or be prohibited. Before purchasing a router with a power output greater than 20 dBm, check local regulations.

How to check the real range of your router?

Theoretical calculations are good, but how do you know how many meters exactly yours Does the router cover the network in practice? Here are the step-by-step instructions:

1. Install a Wi-Fi analyzer app:
   • 📱 Android: WiFi Analyzer or NetSpot.
   • 🖥️ Windows/macOS: inSSIDer or Acrylic Wi-Fi.
2. Measure signal strength (RSSI) at different points:
   • 📊 -30 dBm: excellent signal (maximum speed).
   • 📊 -60 dBm: good signal (minor speed loss possible).
   • 📊 -70 dBm: weak signal (speed drops, interruptions are possible).
   • 📊 -80 dBm and below: The connection is unstable.

Build a coverage map:

• 🗺️ In NetSpot or Ekahau Heatmapper You can create a heat map of the signal.
• 📏 Mark on the floor plan the areas with worse RSSI -70 dBm — repeaters are needed there.

☑️ What do you need to test Wi-Fi coverage?

Install analytical softwareDisable other networks (if possible)Walk around the room with the deviceRecord RSSI at key pointsCompare with standards (-60 dBm and better)

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Example: If in the bedroom (10 meters from the router through 2 walls) the signal level -75 dBm, and the speed drops to 10 Mbps - the problem is not in the power of 20 dBm, but in interference or the wrong channelSolution: Change the channel to a less crowded one (for example, from 6 to 11 in the 2.4 GHz range).

5GHz vs 2.4GHz: How Does Frequency Affect Range at 20 dBm?

Transmitter power is not the only factor. Signal frequency plays no less a role:

• 📡 2.4 GHz:
  • ✅ Better penetration through obstacles (long waves).
  • ✅ Range in open areas: up to 120 m (at 20 dBm).
  • ❌ Strong interference from other devices (microwaves, Bluetooth).
• 📡 5 GHz:
  • ✅ Less interference, higher speed (up to 1 Gbps).
  • ✅ Range in open areas: up to 60 m (at 20 dBm).
  • ❌ More weakened by walls (short waves).

Conclusion: If you need maximum range (for example, for a summer house or a large office), choose 2.4 GHz even with a power of 20 dBm. For high speed within one room - 5 GHz.

How to enable both ranges at the same time?

Most modern routers (for example, Keenetic Giga or Xiaomi AX3600) support dual mode (2.4 + 5 GHz). To activate it:

1. Go to the router's web interface (usually 192.168.1.1).
2. Go to the section Wireless Network → Wi-Fi Settings.
3. Make sure both networks (2.4 and 5 GHz) are enabled and have different names (eg. MyWiFi_2G And MyWiFi_5G).
4. Save the settings and reconnect the devices.

This will allow you to take advantage of both ranges.

How to increase the range at 20 dBm power?

If your router with 20 dBm power does not cover the required area, do not rush to change it. Here 7 proven methods Improve your signal without buying new equipment:

1. Change Wi-Fi channel:

   In apartment buildings, 2.4 GHz channels are often overloaded. Use WiFi Analyzerto find the clearest channel (usually 1, 6, or 11). Select it manually in your router settings (Wireless Network → Channel).

2. Update your router firmware:

   Manufacturers regularly optimize signal transmission algorithms. For example, in firmware for ASUS RT-AX88U After the update, stability at long distances has improved.

3. Adjust the channel width:

   In the 2.4 GHz range, set the channel width 20 MHz (not 40 MHz). This will reduce the speed, but increase the range and stability.

4. Change the location of the router:

   Install it as high as possible (on a cabinet or wall) and in the center of the room. Avoid proximity to metal objects, mirrors, and aquariums.

5. Use external antennas:

   Many routers (for example, TP-Link Archer C7) allow you to connect antennas with amplification 5–9 dBiThis can increase the range by 15–30%.

6. Activate the Signal Booster mode:

   In some models (eg, Zyxel Keenetic) there is an option Extender Mode or Wi-Fi Booster, which optimizes transmission over long distances.

7. Adjust the power manually:

   In advanced routers (for example, on firmware DD-WRT) you can increase the power up to 23–27 dBm via command:

   iwconfig wlan0 txpower 23

   ⚠️ Please note: Exceeding legal power limits may result in fines. In Russia and the EU, the maximum permitted values ​​are 20 dBm for 2.4 GHz And 23 dBm for 5 GHz (without certification).

When 20 dBm Isn't Enough: Alternative Solutions

If all settings are optimized, but the signal still doesn't reach the desired points, consider the following options:

• 🔄 Wi-Fi repeater:

  The device connects to the main network and retransmits the signal. For example, TP-Link RE605X (5 GHz, 300 Mbps) increases coverage area by 30–50 metersCons: Speed ​​drops by 30–50% due to double data transfer.

• 📶 Mesh system:

  A set of 2-3 knots (eg Google Nest WiFi or ASUS ZenWiFi), which create a unified network without speed loss. Ideal for homes over 100 m².

• 🌐 Wired bridge (Powerline):

  Adapters TP-Link AV1000 They transmit internet through electrical wiring and then distribute it through an additional router. Speeds up to 500 Mbps, range up to 200 m via wires.

• 📡 Directional antenna:

  For communication between buildings (for example, a house and a garage), an antenna is suitable Ubiquiti NanoBeam M5 (23 dBi). Range up to 500 meters with direct visibility.

The cost of solutions varies from 1 500 ₽ (repeater) to 20 000 ₽ (3-node mesh system). The choice depends on your budget and the task:

• 🏡 For an apartment: a repeater or a 2-node mesh.
• 🏠 For a private home: Mesh system or Powerline + router.
• 🏢 For the office: several routers in mode WDS (seamless roaming).

FAQ: Frequently asked questions about Wi-Fi router power

❓ Is it possible to increase the router's power above 20 dBm?

Technically yes, but it could be illegallyIn most countries, power is limited:

• 🇬🇧 Russia: before 20 dBm (100 mW) for 2.4 GHz, 23 dBm (200 mW) for 5 GHz.
• 🇪🇺 EU: up to 20 dBm for 2.4 GHz.
• 🇺🇸 USA: up to 30 dBm (1 W) for some 5 GHz channels.

Exceeding the limits may cause interference with other devices and lead to fines. If higher power is required, use certified equipment (e.g. Ubiquiti with a license).

❓ Why does a router with 20 dBm only cover 10 meters, although it should cover 20-30?

The reasons may be as follows:

• 🔌 Poor nutrition: If the router is connected via a weak power supply (for example, from a telephone), the transmitter power drops.
• 📵 InterferenceIn apartment buildings, 2.4 GHz channels are clogged with other networks. Try changing the channel to 1, 6, or 11.
• 📡 Weak antennas: built-in high-gain antennas 2–3 dBi worse than external ones 5 dBi.
• 🛠️ Outdated firmware: Older software versions may have a power limitation.

Check first signal strength (RSSI) in the router settings or through the app. If it's worse -70 dBm at a distance of 5 meters - the problem is in the equipment.

❓ Which router with 20 dBm has the longest range?

At the same power 20 dBm the range depends on:

• 📶 Receiver sensitivity (the lower the threshold, the better). For example, ASUS RT-AX86U catches a signal up to -90 dBm, and budget models - only up to -75 dBm.
• 🔄 Number of antennas: models with 4×4 MIMO (For example, TP-Link Archer AX6000) work more stably over long distances.
• 🛡️ Signal processing algorithms: routers with chips Broadcom (For example, Netgear Nighthawk) cope better with interference.

Top 3 models with 20 dBm power and maximum range:

1. ASUS RT-AX88U (4 antennas, sensitivity -90 dBm).
2. TP-Link Archer AX6000 (8 streams, technology Beamforming).
3. Keenetic Giga (KN-1010) (optimized for large spaces).

❓ Does weather affect the range of Wi-Fi with a power of 20 dBm?

Yes, but not as much as mobile communications. Key factors:

• 🌧️ Rain/snow: weaken the signal on 0.01–0.03 dB/km (insignificant for home networks).
• 🌡️ Temperature: at -20°C and below, the performance of the router's electronic components may deteriorate.
• 💨 Wind: If the antennas are installed outdoors, vibration may disrupt the directionality.

Indoors, the weather doesn't affect it. In open areas (for example, communication between houses), it's better to use 5 GHz - This range is less susceptible to atmospheric interference than 2.4 GHz.

❓ Is it possible to use a router with 20 dBm for communication over 500 meters?

No, if we are talking about direct connection without additional equipment. Maximum range for 20 dBm:

• 📡 2.4 GHz: to 120 m in open areas (under ideal conditions).
• 📡 5 GHz: to 60 m.

For communication on 500 meters you will need:

1. Directional antennas with gain 15–23 dBi (For example, Ubiquiti Rocket M5).
2. Mode Point-to-Point (PTP) with antenna alignment adjustment.
3. Transmitter power not less than 27 dBm (license required).

Alternative: Fiber optic cable or 4G/5G router with external antenna.