A worked example
A last period starting April 1, 2026 with a typical 28-day cycle points to a most-likely conception date of about April 15, 2026 — 14 days later.
Frequently asked questions
How is this different from the Due Date Calculator?
Due Date looks forward to when the baby is expected. This looks at the same starting information but solves for when conception most likely happened — useful purely out of interest once you already know you're pregnant.
Why does cycle length matter here?
Ovulation timing shifts with cycle length — it's most useful to think of ovulation as happening a consistent ~14 days before the next period, regardless of how long the overall cycle runs.
This calculator provides estimates for general informational purposes only and is not medical advice.