unrated player -initial rating

How to calculate initial rating of an unrated player.If it is calculated from getting average rating ...how to calculate average rating...??

There's some long formula with lots of stipulations for official ratings.

I'd just take the average of the opponent's ratings (you add all the ratings of the opponents then divide by how many opponents there were).

Then I'd look at what the unrated player scored and compare it to a win expectancy chart.

Basically:

If they scored 50% then their performance was the average rating (AR).
If they scored 65% then their performance was AR +100
75% AR+200
85% AR+300

Similarly if 35%, 25%, or 15%, then -100, -200, -300

Or if you want to be more accurate:

My average is 1618 and I have got 4.5 out of 7 rated players...according to this chart my rating should be average+(99......106).Then it should be around 1710.Am I correct??

Thank you for helping me to get correct information.

Yes, about 1700 would be my guess because that was your performance. I'm not sure how the rating system does it.