Calculadora de Ciclo Menstrual
- Created by
- Renato Passos, Eng. de Software
- Reviewed by
- Renato Passos, Eng. de Software
Last updated: Apr 18, 2026
Formula
próxima = última + ciclo
About this calculator
The Menstrual Cycle Calculator is a tool that estimates the date of your next period based on the date of your last period and your average cycle length. The calculation is simple: add the cycle length to the last period date. For example, if your cycle is 28 days and your last period started on January 1st, the next one will be on January 29th.
This calculator is useful for women who want to track their menstrual cycle, whether for family planning, identifying irregularities, or simply preparing for their period. It can help predict fertile days, but it does not replace contraceptive or fertility methods.
Keep in mind that the menstrual cycle can vary from month to month due to factors like stress, diet, exercise, and health conditions. The calculator assumes a regular cycle, so results are estimates. For better accuracy, track several cycles and adjust the average length as needed.
Use this tool as a guide, not an absolute certainty. Consult a gynecologist if you have concerns about irregularities or are trying to conceive. The calculator is a starting point to better understand your body and cycle.
Frequently asked questions
How do I use the menstrual cycle calculator?
Enter the first day of your last period and your average cycle length in days. Click calculate to see the predicted date of your next period.
What is considered a regular menstrual cycle?
A regular cycle lasts between 21 and 35 days, with the same length each month. Variations of up to 7 days can still be normal.
Can the calculator help me get pregnant?
It can estimate your fertile days, but it does not replace ovulation tracking methods. Consult a doctor for personalized advice.
Why didn't my period come on the calculated date?
Cycles can vary due to stress, illness, weight changes, or other factors. Delays of a few days are common. If delays are frequent, see a gynecologist.
Can I use the calculator if my cycle is irregular?
Yes, but results will be less accurate. Use the average length of your recent cycles. For very irregular cycles, consult a doctor.