Due Date Calculator

Calculate your pregnancy due date based on last menstrual period, conception date, or ultrasound date.

Result

Fill in the fields above, then press Calculate.

A due date calculator estimates your baby's expected arrival date based on your last menstrual period, conception date, or ultrasound, helping you and your healthcare team plan prenatal care.

Select a calculation method: Last Menstrual Period (most common), conception date (if known), IVF transfer date, or ultrasound dating. Enter the corresponding date and the calculator will estimate your due date, current gestational age, trimester, and key milestones.

Examples

LMP method

If your last menstrual period started on January 1, your estimated due date would be October 8 (January 1 + 280 days).

Frequently Asked Questions

How accurate is the due date calculation?
Only about 5% of babies are born on their exact due date. Most are born within 2 weeks before or after. The due date is an estimate to guide prenatal care.
Which method is most accurate?
Early ultrasound dating (before 12 weeks) is generally the most accurate. LMP-based calculations assume a regular 28-day cycle with ovulation on day 14, which varies for many women.
Related Calculators
Pregnancy Calculator
Conception Calculator
Ovulation Calculator
Pregnancy Weight Gain Calculator

Quick Tips

  • •An early ultrasound (before 12 weeks) provides the most reliable due date — ask your provider to confirm.
  • •Use the due date as a guide rather than an exact target, and prepare for delivery 2 weeks before or after.