DueDateCalculatorduedate-calculator.com

Ovulation Due Date Calculator

Track your ovulation? Enter the date you ovulated to get a more accurate due date — especially helpful for irregular cycles.

Conception typically occurs within 24 hours of ovulation. Ovulation and conception dates are treated as equivalent.

Ashok Kumar Poudel
Written by
Ashok Kumar Poudel
Health & Wellness Writer
Dr. Bina Basnet
Medically reviewed by
MBBS, MD — Gynecologist & Obstetrician
Last reviewed:
Feb 2026

Why Use Ovulation for Due Date Calculation?

The standard LMP method assumes everyone ovulates on day 14 of a 28-day cycle. In reality, ovulation varies considerably — some women ovulate as early as day 10, others as late as day 21 or beyond. Using your actual ovulation date eliminates this assumption and gives you a more precise due date estimate. This is especially important if you have longer cycles (PCOS, for example, often delays ovulation) or shorter cycles.

The formula is identical to the conception calculator: EDD = Ovulation Date + 266 days. This reflects the 266-day average from fertilization to full-term delivery. The result is the same due date you’d get if you entered your ovulation date as your conception date.

How to Track Ovulation Accurately

🧪
OPK (LH Test)

Detects LH surge 24–36 hours before ovulation. Most convenient home method.

🌡️
BBT Charting

Temperature rises 0.2°C after ovulation. Confirms ovulation has occurred.

💧
Cervical Mucus

Clear, stretchy 'egg-white' mucus signals peak fertility approaching ovulation.

🔬
Ultrasound

Follicle tracking by a clinician is the most precise ovulation detection method.

Frequently Asked Questions

Common questions answered by our medical team

Add 266 days to your ovulation date. This works because pregnancy lasts approximately 266 days from fertilization/conception, which occurs very close to ovulation (within 24 hours of the egg being released).
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