A good average weight for the neck will be around 12 grains, the insert around 12 grains, and about 8 grains for each standard 4" plastic vane. These aren't the actual weights, but if you don't have a scale to weigh the arrows and you don't know the exact weight of the arrows components then this is just a pretty decent way to get an aproximate total weight. Lets say you are shooting a 28 inch arrow that weighs 9 grains per inch, that leaves the shafts total weight at 252 grains, add the 3 vanes with comes to 24 grains plus the insert and nock, that brings the weight to 300 grains, then add your tip (100 grain would take the arrows total weight to 400 grains). Hope this helped.