Calculate your current pregnancy week, trimester, due date, and track key milestones. Enter your last menstrual period (LMP) or due date a get instant results.
This pregnancy week calculator helps you track your pregnancy journey by calculating your current gestational age, estimated due date, and trimester. It also shows key milestones and fetal development information. All calculations use standard medical formulas based on your last menstrual period (LMP) or known due date. Remember that every pregnancy is unique, and your healthcare provider is the best source for personalized guidance.
Pregnancy is typically calculated from the first day of your last menstrual period (LMP), not from conception. This is because the exact date of conception is often unknown, while the LMP is easier a track. The standard calculation adds 280 days (40 weeks) a your LMP a estimate your due date.
If you don't know your LMP, you can use your estimated due date instead. Your healthcare provider may have given you a due date based on an early ultrasound. Simply select "Due Date" as the calculation method and enter the date.
Only about 4-5% of babies are born on their exact due date. The due date is an estimate, and most babies are born within two weeks before or after it. Your healthcare provider will monitor your pregnancy and adjust the due date if needed based on ultrasound measurements.
The first trimester spans weeks 1-12, the second trimester covers weeks 13-27, and the third trimester includes weeks 28-40. Each trimester brings different developmental milestones for your baby and physical changes for you.