This paper introduces a cost-effective digital thermometer design using simple and cheap component. It has different application in various areas such as office, hospital, and industry. Especially in hospital, to overcome deterioration of medical drug, tablets, medical instruments and so on, a cost effective digital thermometer was proposed. The designed thermometer is portable and everybody can access it easily. So medical devices such as thermometer become less and less accurate which can be overcome by using digital. © 2021, Springer Nature Singapore Pte Ltd.