How to get average of column values in laravel

If you want to do it with the query builder you can use aggregate methods like avg:

$avg_stars = DB::table('your_table')
                ->avg('star');

Laravel 5 docs about aggregates.

If you have more columns you can use the native function of the database manager using DB::raw

$products = DB::table('products')
                 ->select('id','name',DB::raw('round(AVG(quantity),0) as quantity'))
                 ->groupBy('id','name')
                 ->get();

Try this :

$avgStar = Model::avg('star');

" Model " will replace with your model name