Pregnancy Weeks to Months Calculator

This tool converts a pregnancy measured in weeks and days into months, and back the other way. You enter the completed weeks and days your clinic gave you, and it returns the month you are in, the figure in calendar months of 30.4375 days, the same span in four-week months, the trimester and the time left to 40 weeks. The second option takes a month and returns the weeks it covers. A month is not a clinical unit, and 40 weeks is 9.2 calendar months or exactly 10 four-week months rather than a clean nine, which is why published month charts disagree with each other and why the rule used here is printed with the answer.