Due Date Calculator by Conception Date

Pregnancy from conception lasts about 266 days (38 weeks). The calculator subtracts 14 days from the conception date to estimate the equivalent LMP, then adds 280 days. This accounts for the 2 weeks before conception in gestational age.

Not always, but very close. Conception can occur within 12-24 hours of ovulation. Sperm can survive 3-5 days, so intercourse up to 5 days before ovulation can result in conception. The ovulation date is the most common estimate.

Yes, if you genuinely know your conception/ovulation date. Women who track ovulation using OPKs (ovulation predictor kits), BBT charting, or IVF have a more precise conception date than relying on period dates.