Pregnancy due date calculator
Estimate your due date from your last period, conception date, IVF transfer, or an ultrasound. This is a guide only — your care team confirms dating.
Already have a due date? Find your conception date
What an estimated due date means
An estimated due date (EDD) is a planning date, not a deadline. Pregnancy is counted as about 40 weeks from the first day of a typical last period. Only around four in 100 babies arrive on that exact day — most come in the weeks either side.
How this calculator works
Last period adds 280 days, then shifts by how much your cycle differs from 28 days (assuming ovulation about 14 days before the next period). Conception adds 266 days. A day-3 IVF transfer adds 263 days; a day-5 transfer adds 261. Ultrasound uses the gestational age on the scan and counts forward to 40 weeks.
Can the date change?
Yes. A dating scan, irregular cycles, or later growth measurements can move the official date. Use this tool to get oriented, then follow the date your midwife or doctor records.
This calculator is an educational estimate, not medical advice. It does not replace ultrasound dating or clinical care, and it does not compare last-period and scan dates the way a clinic would.