🤰
Conception Calculator
Estimate when you conceived from due date, ultrasound dating, or last period. Shows conception window and fertile days.
HEALTHEstimate when you conceived based on your due date, ultrasound dating, or last menstrual period. Shows the most likely conception date plus the fertile window when intercourse may have led to pregnancy.
For a 28-day cycle, ovulation falls on day 14 of the cycle; conception happens within 24 hours of ovulation. For other cycle lengths, ovulation = cycle_length - 14 days. From a due date, conception = due_date - 266 days. From an ultrasound, conception = scan_date - (gestational_age + 14 days). The conception window spans about 5 days because viable sperm can wait in the fallopian tubes.
Disclaimer: Estimates only. Actual conception date depends on cycle variability and timing of intercourse. Ultrasound dating is more accurate than LMP for most pregnancies.
Loading calculator…
Advertisement
Frequently Asked Questions
What is the Conception Calculator for?
Estimate when you conceived based on your due date, ultrasound dating, or last menstrual period. Shows the most likely conception date plus the fertile window when intercourse may have led to pregnancy.
How do I use the Conception Calculator?
For a 28-day cycle, ovulation falls on day 14 of the cycle; conception happens within 24 hours of ovulation. For other cycle lengths, ovulation = cycle_length - 14 days. From a due date, conception = due_date - 266 days. From an ultrasound, conception = scan_date - (gestational_age + 14 days). The conception window spans about 5 days because viable sperm can wait in the fallopian tubes.
How accurate are my conception results?
Estimates only. Actual conception date depends on cycle variability and timing of intercourse. Ultrasound dating is more accurate than LMP for most pregnancies.
Is the Conception Calculator free to use?
Yes - every calculator on WhichCalc is completely free with no signup, no usage limits, and no tracking on the calculation itself. Results display instantly in your browser and your inputs are never sent to a server. Bookmark the page if you use this calculator regularly.
Sponsored