RSSI range for WiFi icons What is stock RSSI range for the WiFi indicator icon in notification bar?
I didn't look back through older versions, but here's information accurate as of Android 7.1.2.

The code that performs the transformation from RSSI to signal "level" is found in the WifiManager.calculateSignalLevel method:

public static int calculateSignalLevel(int rssi, int numLevels) {
    if (rssi &lt;= MIN_RSSI) {
        return 0;
    } else if (rssi &gt;= MAX_RSSI) {
        return numLevels - 1;
    } else {
        float inputRange = (MAX_RSSI - MIN_RSSI);
        float outputRange = (numLevels - 1);
        return (int)((float)(rssi - MIN_RSSI) * outputRange / inputRange);
    }
}


...where MIN_RSSI is -100 and MAX_RSSI is -55 (source). The input range is "dynamic" in the sense that its based off of how many resource files are available for the WiFi icon, but in AOSP this value will be 5 because it has icons for 0-4 bars. Using the above logic and values, the ranges come out to approximately:


-55 or higher: 4 bars
-56 to -66: 3 bars
-67 to -77: 2 bars
-78 to -88: 1 bar
-89 or lower: 0 bars