Find out when conception likely occurred from a due date, plan your fertile window from your last period, or find the best time to conceive for a target due date.
This calculator has three modes to help with conception planning:
Find conception date from a due date — Works backwards from a known or estimated due date to determine when conception most likely occurred.
Find fertile window from LMP — Given your last menstrual period, calculates your upcoming ovulation date and fertile window for this cycle.
Plan ahead for a target due date — If you have a preferred delivery timeframe, shows which conception windows in upcoming cycles would result in that due date.
Note: These are statistical estimates. Fertility varies significantly between individuals. Consult a reproductive health specialist for personalized guidance.