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What Is a Good WiFi Signal Strength?

A good WiFi signal strength is −67 dBm or stronger (closer to zero). −50 dBm or better is excellent, −70 dBm is the edge of reliable, and anything below −80 dBm will drop out. Because the scale is logarithmic, every 3 dB is about double or half the power.

Updated 3 min read

WiFi signal strength chart (dBm)

SignalQualityGood for
−30 to −50 dBmExcellentMaximum speed, any activity
−51 to −60 dBmVery good4K streaming, gaming, video calls
−61 to −67 dBmGoodReliable HD video and calls
−68 to −70 dBmFairBrowsing, email, SD video
−71 to −80 dBmWeakSlow, may drop
Below −80 dBmPoorBarely connects

Slide to your own reading with the WiFi signal strength checker to see where it lands.

Why are WiFi signal numbers negative?

dBm compares the power you receive to one milliwatt. WiFi signals arrive at a tiny fraction of a milliwatt, so the number is negative. That’s why −40 is stronger than −70: it’s closer to zero.

The scale is logarithmic. A drop from −60 to −63 dBm halves the power, and −60 to −70 dBm is a tenth of the power. That’s why one extra wall can make a big difference.

dBm vs bars vs percentage

The bars on your phone are a rough summary, and each manufacturer draws them differently. Some devices, like Windows, show a percentage. dBm (also called RSSI) is the precise number engineers use. Rough equivalents:

  • 4 bars / 100%: about −50 dBm or better
  • 3 bars / ~75%: about −60 dBm
  • 2 bars / ~50%: about −70 dBm
  • 1 bar / ~25%: about −80 dBm

Signal strength isn’t everything: noise matters

What really decides speed is the gap between your signal and the background noise, called the signal-to-noise ratio (SNR). With noise around −90 dBm, a −65 dBm signal gives an SNR of 25 dB, which is good. In a crowded apartment, noise can be higher, so the same signal performs worse. That’s when changing the band or channel helps; see 2.4 GHz vs 5 GHz and the channel finder.

How to check your WiFi signal strength

  • Mac: hold Option and click the WiFi icon; look for RSSI.
  • Windows: run netsh wlan show interfaces in Command Prompt.
  • Android: look under WiFi → your network → Advanced on some phones, or use a WiFi analyzer app.
  • iPhone: use the WiFi Scanner in Apple’s AirPort Utility app (turn it on in Settings → AirPort Utility).

How to improve a weak WiFi signal

  1. Move the router to a high, central, open spot.
  2. Point external antennas in different directions: one vertical, one horizontal.
  3. Use 2.4 GHz for distant rooms; it travels further.
  4. Add mesh WiFi or a wired access point for large homes.
  5. Re-test with the WiFi speed test to confirm the improvement.

If your signal is strong but WiFi is still slow, the cause is elsewhere. Work through why your WiFi is slow.

Frequently asked questions

Is −70 dBm good?
It’s fair, the borderline for reliable WiFi. Browsing works, but video calls and streaming may stutter. Aim for −67 dBm or better.
Is −50 dBm good?
Yes, −50 dBm is excellent. You’re close to the router and will get full speed.
Can the signal be too strong?
Only in extreme cases, such as a device right on top of the router (around −20 dBm), which can cause errors. Anywhere in normal use, stronger is better.