On its dedicated safety page, the organization recommends that backpack weight should not exceed approximately 15% of the child's body weight. In simple terms: a child weighing 20 kilograms (44 pounds) — a backpack of about 3 kilograms (6.6 pounds) already reaches 15% of their weight. A child weighing 25 kilograms (55 pounds) — about 3.75 kilograms (8.25 pounds). A child weighing 30 kilograms (66 pounds) — about 4.5 kilograms (10 pounds). Check what percentage of body weight the child is about to carry on their back — and also observe how they stand when wearing the backpack.