Let's be honest, doing calculations of any sort on a mobile device is just too cumbersome. There are too many fields to fill out, too many buttons to press, and too many windows to get through. Well, not this time. Two clicks is all you need to enter a last menstrual period, and you’ll immediately see your patient’s due date and gestational age. If you wish, you can then click on the results to view additional details such as trimesters and various commonly-used dates.

Obstetrics Calculator Lite is the free version of Obstetrics Calculator, a much more comprehensive app that offers more calculation types, the ability to save patients, and more. You can find its store listing at: https://play.google.com/store/apps/details?id=com.memre.duedatecalculator3