What is a good Wi-Fi signal strength (dBm)?

A Wi-Fi signal of -50 dBm or stronger is excellent, -60 dBm is good, and -67 dBm is the level Cisco recommends for reliable voice and video calls. At -70 dBm and below, expect slower speeds and the odd dropout. At around -80 dBm, the connection is barely usable. The closer the number is to zero, the stronger the signal.

How to read dBm

Wi-Fi signal strength is measured in decibel-milliwatts (dBm). The numbers are negative because the power that reaches your device is a tiny fraction of a milliwatt. The scale is logarithmic: every 10 dB is a factor of 10 in power. So -70 dBm isn't a little weaker than -50 dBm. It's 20 dB weaker, which is 10 × 10 = 100 times less power.

That's why a few steps or one extra wall can make a big difference. Brick, concrete, mirrors and fish tanks all absorb Wi-Fi signals.

What each level means

These bands are a rule of thumb, not a standard. The -67 dBm line comes from Cisco's guidance. The others are common industry practice:

Signal	Rating	What to expect
-30 to -50 dBm	Excellent	Your device is near the router. Full speed.
-50 to -60 dBm	Very good	Fast and stable for anything, including 4K and gaming.
-60 to -67 dBm	Good	Reliable for streaming and video calls.
-67 to -70 dBm	Fair	Fine for browsing. Calls may stutter at busy times.
-70 to -80 dBm	Weak	Slow speeds, buffering, occasional dropouts.
Below -80 dBm	Unusable	Frequent disconnects.

Cisco's wireless deployment guide for its video devices tells installers to keep the signal at -67 dBm or higher for acceptable voice quality. That's a sensible target for any room where you take calls.

Apple's devices start looking for a stronger access point once the signal drops past a set level. Apple's Wi-Fi deployment guide lists -70 dBm for iPhone and iPad and -75 dBm for Mac. If you have a mesh system, that's roughly where your device starts thinking about switching nodes.

Signal strength isn't the whole story

A strong signal can still give you poor Wi-Fi if the air is noisy. What matters is how far the signal sits above the background noise. This is the signal-to-noise ratio (SNR). Cisco Meraki's SNR guide recommends 20 dB or more for data and 25 dB or more for voice.

Here's the arithmetic: a -65 dBm signal with a noise floor of -90 dBm gives 25 dB of SNR, which is good. The same -65 dBm signal with noise at -80 dBm gives only 15 dB, which isn't. Apartment buildings with dozens of networks on the same channel tend to have this problem. Changing the Wi-Fi channel can help more than moving the router.

How to see your signal strength

• Mac: hold the Option key and click the Wi-Fi icon in the menu bar. You'll see RSSI and Noise in dBm, so you can work out SNR yourself.
• Windows: open Command Prompt and run netsh wlan show interfaces. The Signal line is a percentage. Microsoft's WLAN documentation defines 0% as -100 dBm and 100% as -50 dBm, on a straight line between them. To convert, take half the percentage and subtract 100. So 70% is 35 − 100 = -65 dBm, and 40% is -80 dBm.
• iPhone and iPad: iOS doesn't show dBm in Settings. Apple's free AirPort Utility app has a Wi-Fi scanner you can turn on in its settings, which lists RSSI.
• Android: the network's details page usually gives a word such as Excellent or Fair. For dBm, use a Wi-Fi analyzer app.
• Router app or admin page: many routers list every connected device with its signal strength. This is the easiest way to check a smart TV or console.

The bars in your status bar are a rough summary, and each manufacturer draws them differently. Don't rely on them to compare two devices.

Signal versus speed

Signal strength decides your device's link rate, which is the top speed it can talk to the router at. Your real internet speed is lower, and depends on your plan and how busy the network is. To find out what a spot in your home actually gets, run a Wi-Fi speed test there and write down the dBm next to the result. Do the same in two or three rooms and you'll see where the signal starts to cost you speed.

How to get a stronger signal

1. Move the router. Put it high, near the middle of the home, out in the open and away from metal and the microwave.
2. Pick the right band. 5 GHz is faster but fades sooner through walls. 2.4 GHz reaches further but is slower and more crowded. See 5 GHz vs 2.4 GHz.
3. Fix interference before buying hardware. A cleaner channel improves SNR without changing the dBm at all.
4. Add an access point or a mesh node where the signal is below about -70 dBm. Connecting it to the main router by cable works best.
5. Use Ethernet for anything that doesn't move, like a TV, console or desktop PC.

How to boost your Wi-Fi signal goes through each of these step by step.