The conception calculator can be used to estimate the date of pregnancy conception. Conception calculators use the first day of the previous menstrual cycle to estimate the date of conception. Models are based on your menstrual cycle length and the estimated time of ovulation. Ovulation is the time when the female body is primed for conception.

How Can a Conception Calculator be Used?
Conception calculator uses differ from one woman to the next. If a woman has had unprotected sex with more than one man, she may want to use the conception calculator to give her an idea who the father may be. If there is no menstrual cycle between the bouts of unprotected sex, a conception calculator will not effectively reveal paternity. Only a paternity test will reveal the true father of the child in this case.

Common Questions about Conception Calculator Models
There are many questions floating around about the conception calculator. Here are a few of the more common and answers to these questions.

How accurate is a conception calculator?
There is no way of knowing the exact date of conception unless a woman tracks her cycle and has unprotected intercourse only once per cycle. The conception calculator will give a woman an estimated date of the probable time when conception occurred.

Could the conception calculator be wrong?
Yes, a conception calculator can be wrong. Ultrasounds can also be wrong as can home pregnancy tests. There is no perfect system for estimating conception date unless intercourse happened only once between menstrual cycles.

Why does the ultrasound give a different date of conception than a conception calculator?
A conception calculator will use the first day of the last menstrual cycle to determine the probable date of conception. An ultrasound uses the size of the fetus to estimate gestational age. Ultrasound dating can change throughout pregnancy based on the size of the fetus, but the conception calculator will always offer the same probable date of conception based on the last menstrual cycle and length of the average menstrual cycle.

What is the difference between an online conception calculator and the “wheel” conception calculator an obstetrician uses?
There is no difference between the two. The doctor uses the first day of your last menstrual cycle to estimate due date and conception date in much the same way the online conception calculator works.

A conception calculator is a tool pregnant women can use to estimate the date of delivery or the date of conception. All results are based on input, so women need to know the accurate first day of their last menstrual cycle to achieve the best, and most reliable, results.