Conception Calculator
Estimate possible conception and fertile-window dates from cycle data.
This page is an editable estimator with realistic defaults so you can model your own situation in minutes.
Estimated conception is near ovulation, calculated as last period date plus cycle length minus 14 days.
Treat the result as a planning estimate and verify important numbers with the relevant official source before acting.
| Last period | May 9, 2026 | |
|---|---|---|
| Cycle length | 28 days |
Assumptions
- Conception is most likely near ovulation, but sperm and egg timing varies.
- This calculator cannot confirm pregnancy or exact conception date.
How this calculator works
Formula used
Estimated conception is near ovulation, calculated as last period date plus cycle length minus 14 days.
Example calculation
Plug in your own numbers and the result updates instantly. Estimated conception is near ovulation, calculated as last period date plus cycle length minus 14 days.
Conception Calculator FAQ
Is this conception calculator medical advice?
No. It is an educational estimate only and does not replace an OB-GYN, midwife, fertility specialist, pediatric clinician, or emergency care.
Why might my actual dates or recommendations differ?
Cycle length, ovulation timing, ultrasound dating, implantation timing, multiples, medical history, and clinician judgment can change pregnancy and fertility estimates.
Should I confirm results with a clinician?
Yes. Confirm pregnancy dating, weight gain, cycle concerns, fertility timing, or health decisions with a qualified healthcare professional.