To facilitate administration of praziquantel (PZQ) to African infants and preschool-aged children using a dose pole, the performance of two downwardly extended versions (the first created in 2010 using biometric data from Uganda alone and the second version created here using data from 36 countries) was assessed against height/weight data from a total of 166 210 preschool-aged children (=6 year olds) from 36 African countries. New and optimized thresholds for PZQ tablet administration at one tablet (600 mg), ¾ and ½ tablet divisions are suggested here. Both dose poles investigated estimated an acceptable PZQ dosage (30–60 mg/Kg) for more than 95% of children. Extension and optimization of the current PZQ dose pole, followed by theoretical validation using biometric data from preschool-aged children (0–6 years of age, 60–110 cm in height) from 36 African countries will help future mass drug administration campaigns incorporate younger children. This newly optimized dose pole with single 600 mg (height: 99–110 cm), ¾ (height: 83–99 cm) and ½ (height: 66–83 cm) tablet divisions, also reduces drug waste and facilitates inclusion of preschool-aged children. Our findings also have bearings on the use of other dose poles for treatment of young children.