How Much Should a School Backpack Weigh? What the 10% Rule Gets Wrong By Chester Takau · October 2026 The short answer: Most guidance says 10% of your child's body weight, with 15% as the ceiling. A 70 lb child would carry about 7 lb, and no more than about 10 lb. But the American Academy of Pediatrics (AAP) said in August 2026 that there isn't enough evidence to make the 10-15% rule a universal limit. It advises keeping the pack as light as possible and watching the child: leaning forward, trouble walking, or straps digging into the shoulders mean it is too heavy, whatever the scale says. Sources don't agree on one number. The National Safety Council says 5-10%, Cleveland Clinic says 10% is ideal and 15% is the most a child should carry, and KidsHealth gives 10-20%. This page lines them up, gives you a calculator for your child's weight, and covers what two 2026 reports say about whether the percentage rule holds up. Chester Takau, TokMind ...