Pregnancy Due Date Calculator
Calculate your pregnancy due date and current week based on last menstrual period (LMP)
Last Menstrual Period (LMP)
About the Pregnancy Due Date Calculator
This pregnancy calculator uses Naegele's Rule to estimate your due date by adding 280 days (40 weeks) to your last menstrual period (LMP). It also calculates your current pregnancy week, day within that week, trimester, and the days remaining until your due date. A full-term pregnancy typically lasts between 37 and 42 weeks. Note that this calculator provides an estimate — only a healthcare provider can confirm your actual due date.
FAQ
- How is the due date calculated?
- The due date is calculated using Naegele's Rule: add 280 days (40 weeks) to the first day of your last menstrual period (LMP). This is the standard method used by most healthcare providers worldwide.
- What are the three trimesters of pregnancy?
- Pregnancy is divided into three trimesters: the first trimester covers weeks 1–12, the second trimester covers weeks 13–26, and the third trimester covers weeks 27–40. Each trimester brings different developmental milestones.
- Is the calculated due date accurate?
- The calculated due date is an estimate based on a standard 28-day menstrual cycle. It may vary if your cycle is irregular. Only about 5% of babies are born on their exact due date. Always consult your OB/GYN for a confirmed due date via ultrasound.
Related Tools
Date Calculator
Calculate the difference between two dates in days, weeks, months, and years
Military Discharge Calculator
Calculate military discharge date based on enlistment date and branch
Menstrual Cycle Calculator
Calculate next period, ovulation date, and fertile window
Percentage Calculator
Calculate percentages, discounts, increases, and percentage differences