Every flight planner and pilot needs to know the accurate total of the payload and the weight of each piece of cargo to balance the load. If you must come prepared with your truthful weight clearly written on more than one card and hand that card to whoever on the crew asks. Be prepared to be asked more than once as both the total load is calculated and the balance is determined. Each plane, cargo load, fuel load, and current temperature will add variables. Some days they may just look and guess using a chart, other days the numbers may require much closer inspection either with an oral question and answer or actual scale weighing with each passenger and carry on. Yes, your 20 pound purse counts...