How to find beacon distance by the received RSSI? in Android

1

Please tell me how to find the distance buy the received rssi of a respective beacon

2 
  public double getDistance(int measuredPower, double rssi) {
    		if (rssi >= 0) {
    			return -1.0;
    		}
    		if (measuredPower == 0) {
    			return -1.0;
    		}
    		double ratio = rssi * 1.0 / measuredPower;
    		if (ratio < 1.0) {
    			return Math.pow(ratio, 10);
    		} else {
    			double distance= (0.42093) * Math.pow(ratio, 6.9476) + 0.54992;
    			return distance;
    		}
       }
3

hi hell
I am calling getdistance method in monitoring and ranging also.but why it is not calling everytime.please reply me as fast as possible…

Thanking you…

4

the above distance formula returns in distance in what parameters like centimeters or meters etc…