How to use the Gestational Calculator?

Our online gestational age calculator allows you to calculate how many weeks your baby is in three different ways. The easiest way to use the gestational calculator is to simply enter the first day of your last period. If you don’t know when the first day of your last period was, you can use these other ways:

Probable Delivery Date (or DPP) : knowing when your baby’s expected date of birth is, just put that day on the calculator. It will inform you of your current gestational age, the likely date of conception and everything else that is important in your pregnancy. But be warned, PPD is not the day you are scheduling the delivery! The expected date of delivery is the day you turn 40 weeks old .

Last Menstruation Date (or LMP) : this is the most commonly used parameter, the first day of the last menstruation. With information we can understand your menstrual cycle and determine all the important events of your pregnancy.

Date of a previous exam : use if you do not know when your last menstrual date was or when your probable delivery date is. That way it is not possible to calculate using your menstrual cycle, so we need to use ultrasound. But attention you should always use the first examthat was performed in this pregnancy so that the calculation is accurate. This recommendation is due to the fact that the ultrasound margin of error is smaller the earlier it is. If you choose to use this parameter for the calculation, you will need to enter, in addition to the date the exam was performed, the gestational age that was estimated in that exam. For example, if you took an exam on 5-10 you estimated the gestational age and 8 weeks and 3 days. In this case, you must use the value of 10/05 for calculation in the field “Date of a previous exam” and in gestational age you must enter 8 weeks and 3 days.

If you are completely lost with these dates of your pregnancy consult your prenatal portfolio. This information should contain all the information about your pregnancy and should be easily found.

I don’t understand how to calculate gestational age in weeks, maybe in months?

No, the technically correct way to calculate gestational age is in weeks. Using months is a lay and very inaccurate way to count your pregnancy time. Months do not have the same number of days. Yes, it is only 1 day apart from one month to the next, but that added to 9-10 months gives a considerable difference. Furthermore, if we say that someone is in the 7th month, there is a very big difference between the beginning and the end of the 7th month. Therefore, there are several reasons to count gestational age in weeks rather than months. If you are having trouble understanding how this happens we have prepared two very cool posts on the subject and we recommend that you read as soon as possible:

How is Gestational Age (Duration of Gestation) calculated?
Gestational Age in Months

I’m still trying to get pregnant… how do I do it?

In this case you don’t need the gestational calculator, but the Fertile Period Calculator . With it it is possible to inform some characteristics of your menstrual cycle to know what is the probable day of your ovulation. This makes it possible to determine the period when your chances of becoming pregnant are greatest.