The present invention is directed towards a device, method of using a device, and a method of making a device for predicting weight and/or the appropriate dose of a medication and/or degree of some other medical intervention in a child. The device includes one or more strips for taking a girth and a length measurement from an individual. The method includes adding or otherwise combining a value given by a girth measurement and a value given by a length measurement together to estimate the weight of the individual.