How conception timing is estimated
Conception is most likely to occur during the fertile window: the day of ovulation and the five days beforehand, since sperm can survive in the reproductive tract for several days while an egg survives about 12-24 hours after release.
How this calculator works
Most cycles have a fairly consistent luteal phase (the time from ovulation to the next period) of about 14 days, so ovulation is estimated by subtracting 14 from your average cycle length. Enter how many days have passed since your last period started and your typical cycle length to see your estimated ovulation day, fertile window, and how many days remain until each from today.
This tool provides general educational estimates only, not medical or fertility diagnosis. Actual ovulation timing varies by individual and cycle; ovulation predictor kits, basal body temperature tracking, or a healthcare provider can offer more precise information.