It is if you know how much your components weigh...you can find it any manufacturers specs...

Nearly everyone has the weights for inserts, nocks and fletching listed. Much easier than getting an (and this is key) accurate FOC measurement by balancing the arrow, subtracting this, adding that, multiplying by Pi, etc

EDIT: For example..I have 111 grains on the front of my A/C/Cs... point and insert..I have 21 grains on the back...4" feathers , uni and nock... divide 111 by 21...and there ya go...