Stunting is one of nutritional problems faced in the world, especially in poor and developing countries. Stunting is a problem that is associated with an increased risk of morbidity and death, suboptimal brain till late motor development and stunted mental growth. Stunting is a condition of growth faltering due to the accumulation of nutrient insufficiency that lasts from pregnancy to 24 months after the delivery. This situation may be worsened by unbalanced catch up growth. In 2018, Basic Health Research Registry (Riskedas) mentioned that 30.8% children in Indonesia experienced stunting. The length and wieight measurement of children becomes very important to determine between a normal and an abnormal condition by calculating the anthropometry and Z-score. Up to now, the measurement was done manually. This study discusses the design of an Arduino microcontrooler based length and weight of children using ultrasonic and load cell sensors. The data from sensors were processed in the microcontroller and displayed on an LCD. The desaigned instrument could also be operated in a bluetooth mode so that the results could be presented in a smartphone via a bluetooth interface. The validation of an ultrasonic sensor as a body length detector had an ideal installation at a height of 23 cm from surface of the pad, showing a regression value of 0,9999. The validation of a loadcell sensor as a body weight detector showed a regression value of 1 with a calibration factor of 212. The functionallity testing of a Graphical User Interface (GUI) in the smartphone, showing all nutritional statuses and Z-score of the measured child are as accurate as on the LCD.