How do we calculate losses in transmission and distribution system of 415 Volts/11KVA network?

I have built a Microhydel power project of50 Kilowatts to electrify106 households of a small village. I installed a step up transformer of62.5 KVA at power house and installed two step down transformers of25 KVA each at distribution side. The total distance of Transmission is5 Kilometer and that of Distribution line is8 Kilometer. I want to transmit power at415/11KVA . PLEASE HELP ME HOW I CALCULATE THE LOSSES IN TRANSMISSION AND DISTRIBUTION NET WORK.