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ARVENRA
Pregnancy & reproductive health

Pregnancy Conception Calculator

The estimated conception window from your current pregnancy dates.

Conception is not a precise moment but a window of about six days, because sperm survive up to five days and the ovum about one.

Your details

From the first day of one period to the first day of the next. Default 28 days.

Typical range: 20 – 45

The values you enter are calculated in your browser only — nothing is stored or transmitted.

Fill in your details and press calculate — your result will appear here.

Formula and method

Ovulation and the fertile window are derived from the last menstrual period and cycle length.

Formula used

Conception window derived from LMP and cycle length

Assumptions and limits

  • The window is an estimate; a precise conception date cannot be established from a calendar.

Scientific sources

  1. American College of Obstetricians and Gynecologists. “Committee Opinion No. 700: Methods for Estimating the Due Date.” Obstet Gynecol. 2017;129(5):e150-e154.

    View source

  2. Wilcox AJ, Weinberg CR, Baird DD. “Timing of sexual intercourse in relation to ovulation.” N Engl J Med. 1995;333(23):1517-1521.

    View source

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