Pregnancy Conception Calculator

Estimates the exact window during which fertilization and intercourse occurred based on baby's due date or ultrasound dating.

Pregnancy & Women's Health• Gestational Reverse Dating (EDD - 266 Days)

Back-calculate probable conception and intercourse dates from your expected due date.

Expected Due Date (EDD)

Probable Fertilization DateAugust 3, 2026Intercourse Window: July 29, 2026 – August 4, 2026

Estimated LMP of Conception CycleJuly 20, 2026

Evidence-based estimations. Consult a physician for personalized guidance.

Clinical Formula & Calculation Standard

Official clinical definitions and validated mathematical models

Estimated Conception Date = Estimated Due Date (EDD) - 266 Days

Back-calculates the probable fertilization window from known obstetric delivery dates or mid-pregnancy ultrasound dating.

The intercourse window spans from 5 days prior to the estimated conception date up through the day of conception.

Track pregnancy progress, current week, trimester, and key developmental milestones.

Calculate estimated date of delivery (EDD) based on LMP, conception, or IVF date.

Track healthy weekly weight gain targets during pregnancy based on pre-pregnancy BMI.