We do not own a scale. Go by how much each bag should cover. 50lb bag that covers 10k ft, use the whole bag on a 10k lawn, 1/2 bag on 5k lawn etc. Thats how we've done it for 35 years. Takes some experience but our techs are damn good at it. We are 100% liquid now with only doing granular on people who want it so we don't have to do this often.