Estimate your due date, track trimester progress, and see key pregnancy milestones week by week.
⚕️ Disclaimer: This calculator provides estimates only. Only about 4% of babies arrive on their exact due date. Consult your OB-GYN for accurate pregnancy dating via ultrasound.
The Due Date Calculator estimates when your baby is due and tracks trimester milestones from your last menstrual period or conception date, so you can count down the weeks with confidence.
The standard method (Naegele's rule) adds 280 days, or 40 weeks, to the first day of your last menstrual period. If you know your conception date, the calculator adds 266 days instead.
It is an estimate — only about 1 in 20 babies arrive exactly on the due date. Most are born within two weeks either side. An ultrasound dating scan gives the most accurate estimate.
Pregnancy is divided into three trimesters: first (weeks 1-12), second (weeks 13-27), and third (weeks 28-40). The calculator shows which trimester you are in and key milestones.
Yes — free, no signup, and all calculations stay in your browser.