ACS712 Current Sensor Code

Ok, Here is what i've reached so far, i found this code on http://www.lucadentella.it/en/2011/11/29/sensore-di-corrente-con-arduino

void setup() {
 
  Serial.begin(9600);
}
 
void loop() {
 
  float average = 0;
  for(int i = 0; i < 1000; i++) 
  {
    average = (average + (((0.0264 * analogRead(A0)) - 13.51)/1000));
    delay(1);
    
  }
  Serial.print (average, 3);
  Serial.print("   ");
  Serial.println(analogRead(A0));
   
}

it doesn't get me accurate readings though, don't know what seems to be the problem.