Pregnancy Calculator

What is a Pregnancy Calculator?

A pregnancy calculator is a simple tool that estimates your due date (EDD), conception date, and key milestones based on the first day of your last menstrual period (LMP). It helps expectant parents anticipate the baby’s arrival, plan for trimesters, and understand the 40-week gestation period. In 2025, with 1 in 6 couples facing infertility and average U.S. pregnancies lasting 280 days (CDC data), a pregnancy calculator reduces uncertainty, though only 4% of births occur on the exact EDD.

This pregnancy calculator uses Naegele’s Rule: Add 7 days and 3 months to the LMP (or +280 days). It assumes a 28-day cycle; adjust for irregularities. Outputs: EDD, conception (LMP + 14 days), trimesters (1st: Weeks 1-12, 2nd: 13-26, 3rd: 27-40). Quick and private—consult a doctor for ultrasounds or concerns.

Related keywords: due date estimator, LMP calculator, conception date tool, gestational age, pregnancy timeline.

How the Pregnancy Calculator Works

  1. Input: Enter LMP date (DD/MM/YYYY).
  2. Base Calculation: Ovulation ~LMP + 14 days. Conception around then.
  3. EDD: LMP + 280 days (40 weeks). Or Naegele’s: LMP + 7 days, +3 months, -1 year if needed.
  4. Milestones: Trimesters, viability (24 weeks), full-term (37 weeks).

Sample: LMP: 15/12/2024. Ovulation: ~29/12/2024. EDD: 21/09/2025. 1st Trimester Ends: 06/03/2025.

Pregnancy Timeline

  • Weeks 1-4: Implantation; hCG rises.
  • Weeks 5-8: Embryo develops organs; heartbeat detectable.
  • Weeks 9-12: Fetus stage; ultrasound for dating.
  • Weeks 13-26: Viability; quickening (movement).
  • Weeks 27-40: Growth; labor possible after 37 weeks.

Tips: Track with apps (Ovia, What to Expect); folic acid 400mcg daily; prenatal visits from 8 weeks.

Frequently Asked Questions

Can the Due Date Change?

  • Yes—first-trimester ultrasound adjusts if LMP uncertain (e.g., irregular cycles).

How Accurate?

  • ±5 days; 50% births within 1 week of EDD.

Conception Date?

  • ~2 weeks after LMP; sperm survives 5 days, egg 24 hours.

Early Testing?

  • hCG detectable 10-14 days post-conception; wait missed period for 99% accuracy.

Disclaimers

This pregnancy calculator estimates—actual EDD from ultrasound. Not medical advice; consult OB-GYN for irregularities, symptoms, or risks. CDC/ASRM data (2025). No liability.

Track your pregnancy—calculate now.

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