Calculadora de Ovulação Online Grátis
Predict your ovulation date and fertile window based on your cycle length
Ovulation is the release of a mature egg from the ovary — the single event that makes conception possible each cycle. This calculator predicts your estimated ovulation date and the 6-day fertile window surrounding it based on your last period and typical cycle length. It's a practical starting point for natural family planning or for couples trying to conceive.
Frequently Asked Questions
Sobre Esta Calculadora
Ovulation occurs when a surge in luteinizing hormone (LH) triggers the release of a mature egg from the dominant follicle, usually 12–16 days before the next menstrual period. This timing is more consistent than counting forward from the last period, which is why cycle length matters for accurate prediction.
The fertile window spans about 6 days: five days before ovulation (because sperm can survive in the reproductive tract) plus the day of ovulation itself. The day before and the day of ovulation carry the highest pregnancy probability — roughly 25–30% per cycle in healthy couples.
Calendar-based ovulation prediction works best for women with regular cycles. For more precise timing, ovulation predictor kits (OPKs) detect the LH surge 12–36 hours before ovulation, while basal body temperature (BBT) charting confirms ovulation has occurred after the fact.
A ovulação é a liberação de um óvulo. Saiba seus melhores dias.
Fórmula
Ovulation Day = LMP + (Cycle Length - 14 days) Fertile Window = Ovulation Day -5 to +1
Exemplo Resolvido
Ovulation prediction for a 26-day cycle
Entradas:
- First day of last period: May 1, 2025
- Cycle length: 26 days
Passo a Passo:
- Estimated ovulation: LMP + (Cycle Length − 14) = May 1 + (26 − 14) = May 1 + 12 = May 13
- Fertile window start: May 13 − 5 days = May 8 (sperm can survive 5 days)
- Fertile window end: May 13 + 1 day = May 14 (egg viable 12–24 hours after release)
- Peak fertility days: May 12–13 (2 days around ovulation)
- Next period expected: May 1 + 26 = May 27, 2025
Dicas
- Sperm can survive up to 5 days, but eggs only 12–24 hours — the fertile window is wider than ovulation itself.
- Ovulation timing varies even in regular cycles — track 3+ months for best accuracy.