Jenny
It goes by weight.
12 ml for weight 66-72 pounds
14 ml for weight 73-80 pounds
My guess is that your 5 year old weighs less than that. If your child weighs 26-33 pounds, the correct dosage is 1 tsp (5ml). If your child weighs 40-45 pounds, the correct dosage is 1 1/2 tsp (7ml).