For failure to thrive (FTT) management and supervised feeding, a clinician needs to calculate weight gain per day over a time interval, which this app does. Finally, clinicians have to practice at hospitals and offices where a variety of units are used for length, weight, and temperature. This app converts any measurement into all appropriate units instantly. The app answers questions such as - this baby was born 7 lbs 2 oz, what weights would represent 5%, 10%, and 15% weight loss? - this baby now weighs 6 lbs 11, what percentage weight loss is that? - the FTT infant I'm caring for weighed 8 lbs 3 oz last week, and now 9 days later weighs 8 lbs 6.5 oz, what weight gain per day in grams would that be? - what is the length in centimeters of a baby born 19 1/4"? This app offers no medical management guidance. It just assists clinicians to transform various measurements into the data one needs to make management decisions. As an educator and clinician myself, I am eager for feedback, including more calculators which might serve pediatricians and family physicians caring for newborns and infants in hospital and clinic.