Calculadora de Data de Fecundação
- Created by
- Renato Passos, Eng. de Software
- Reviewed by
- Renato Passos, Eng. de Software
Last updated: Apr 18, 2026
Formula
fecundação ≈ DUM + 14
About this calculator
The Fertilization Date Calculator estimates the likely time when fertilization occurred, based on the last menstrual period (LMP). For a regular 28-day menstrual cycle, ovulation and fertilization occur approximately 14 days after the first day of the LMP. The tool adds 14 days to the LMP to provide an estimated fertilization date.
This calculator is useful for women who want to identify the most fertile period of their cycle or to better understand the beginning of pregnancy. It is important to remember that the calculation assumes regular 28-day cycles; shorter or longer cycles may change the actual ovulation date. The tool serves as a guide and does not replace medical evaluation.
It is recommended to use the calculator along with other ovulation tracking methods, such as ovulation tests or basal body temperature monitoring. If you have questions about the fertilization date or pregnancy, consult an obstetrician for personalized and accurate assessment.
Frequently asked questions
Does the calculation work for irregular cycles?
It is not accurate for irregular cycles. The calculator assumes a 28-day cycle; for different cycles, ovulation may occur on different dates.
Is the fertilization date the same as the conception date?
Yes, fertilization and conception refer to the same event: the union of egg and sperm.
Can I use this calculator to avoid pregnancy?
No, it is not a contraceptive method. It only estimates the probable fertilization date, without enough accuracy to prevent pregnancy.
What is the difference between fertilization date and last menstrual period?
The last menstrual period is the first day of the cycle. Fertilization occurs about 14 days later, during the fertile window.
Does the calculator replace an ultrasound for pregnancy dating?
No. Ultrasound is more accurate and recommended to confirm gestational age.