Free, private calculators for cycle timing, pregnancy dates, and baby growth and sleep.
Last updated April 25, 2026
Predict your next period and see your cycle on a calendar.
Estimate your ovulation day and fertile window from your LMP and cycle length.
Estimate when you conceived from a due date or LMP, with cycle adjustment.
Estimate your due date from your last period, conception date, or a known due date.
Lunar-age novelty chart for entertainment, not a clinical predictor.
Estimate growth percentiles for weight, length, and head circumference, 0 to 5 years. See methodology for source details.
Look up sleep ranges by age, 0 to 18 years. See methodology for source details.
See how DueDateLab calculates results and handles source notes.