Side-by-side comparison helps you choose the right calculator for a specific clinical question.
Obstetrics
Estimate your ovulation date and fertile window using cycle length and last period date. See best days to conceive and estimated due date if conception occurs.
Formula
Estimated ovulation date = projected next period - 14 days
Inputs
Obstetrics
Predict your next period date using your last menstrual period and average cycle length. See cycle day, fertile window, and upcoming period dates.
Formula
Next period start = LMP + n x cycle length; ovulation estimate = next period - 14 days
Inputs