In Estimote 2.4 version i used ESTBeacon class and calculate distance of iBeacons. Now in Estimote 3.0 version How to calculate distance of iBeacons ?
Use the accuracy property of CLBeacon instead. In fact, the old ESTBeacon's distance was just a renamed accuracy. However, we can’t be sure accuracy is actually the distance estimation (although it does shrink the closer you get to the beacon, and grows the further away you get, so it works like distance), so we decided to stop doing that. (accuracy is provided by iOS’s Core Location API itself, and not the Estimote SDK)