Pregnancy Due Date & Trimester Calculator — ZYCalculator

A pregnancy calculator estimates the delivery due date using Naegele rule (LMP + 280 days) and tracks gestational age, trimester progression, and fetal milestones.

Formula & Method

Estimated Due Date (EDD) = LMP + 280 Days + (Cycle Length - 28 Days)

How to Use

  1. Select Calculation Method: Choose Last Menstrual Period (LMP), Conception Date, or Known Due Date.
  2. Set Cycle Length: Adjust average menstrual cycle length (default 28 days) for clinical accuracy.
  3. View Delivery Due Date & Fetal Growth: Track gestational weeks, trimester progression, baby size fruit comparisons, and key scan dates.

Frequently Asked Questions

How do I calculate my estimated pregnancy due date (EDD)?

Choose Last Menstrual Period (LMP), Conception Date, or Known Due Date. ZYCalculator uses Naegele’s rule (LMP + 280 days) to accurately predict delivery due date.

What are the three trimesters of pregnancy?

First Trimester: Conception to Week 13; Second Trimester: Week 14 to Week 27; Third Trimester: Week 28 to Week 40+.