How to calculate RSSI in dBm for SX1302 + SX1250

I am using Semtech LoRa® Corecell reference design V1.0 (which has SX1302 and SX1250) and testing Receive and Transmit examples. While receiving packets, packet information are printed on console which has RSSI channel and RSSI signal value but those values are in dB.

Is there any equation to convert those values in dBm?

Nileshkumar Vora