Calculate your estimated due date based on your last menstrual period (LMP). Track your pregnancy weeks, current trimester, and days remaining.
The due date is calculated by adding 280 days (40 weeks) to your last menstrual period (LMP). Most babies arrive within ±2 weeks of the due date. Ultrasound dating in the first trimester is more accurate than LMP-based dating.
If you don't know your LMP, an ultrasound (typically done at 8–12 weeks) can estimate your due date quite accurately. Your healthcare provider can help determine your conception date and adjust your due date accordingly.
Trimester 1 spans weeks 1–13, Trimester 2 is weeks 14–27, and Trimester 3 is weeks 28–40. Each trimester brings different changes, developments, and typical prenatal care visits. Your doctor will monitor specific milestones at each stage.
No—due dates are estimates. Only about 5% of babies arrive on their exact due date. Healthcare providers consider any delivery between 37–42 weeks "on time." If you go past 42 weeks, your doctor may discuss induction options.