Pregnancy Week Calculator

This tool counts how far along a pregnancy is on a given day. Enter the first day of the last period, or an estimated due date, and it returns the gestational age in weeks and days, the trimester, the due date and how much time is left. Leave the second date blank to count up to today, or fill it in to check any other date. The figures are date arithmetic from what you enter, so an ultrasound date from your clinic takes precedence over this estimate, and nothing here assesses anyone's health.