How to Calculate the distance with the rssi value and tx power??

[vprasath]

How to calculate the Distance between the central and peripheral where the peripheral is transmitting power at -40 dBm and my rssi value is -100 dBm ?

I'm using the nRF52 DK!!

[awneil]

This has been discussed very many times before.

You really can't do a precise distance calculation purely from RSSI - there are just far too many other variables concerned.

The best you can do is to broadly distinguish "near" from "far".

EDIT

https://devzone.nordicsemi.com/search?q=calculate%20distance%20rssi