Depending on your OS and application, WiFi signal strength is represented either as quality in percentage, or an
RSSI value in dBm, i.e. -70db.
RSSI is usually expressed in decibels relative to a milliwat (dBm) from zero to -120dBm and the closer it is to zero, the stronger the signal is.
RSSI level less than -80dBm may not be usable, depending on noise.
While there is no simple precise solution that is used universally, we will try to explain the approximate correlation between signal (
RSSI) and quality (percentage).
Generally,
dBm >= -50 dBm = 100% quality
dBm <= -100 dBm = 0% quality
For
RSSI signal between -50dBm and -100dBm,
quality ~= 2* (dBm + 100)
RSSI ~= (percentage / 2) - 100
For example:
High quality: 90% ~= -55dBm
Medium quality: 50% ~= -75dBm
Low quality: 30% ~= -85dBm
Unusable quality: 8% ~= -96dBm
See also:
How to read RSSI/signal and SNR/noise ratings ?Note: Most networks can work well with signal over -80dBm.
