Free · Health · Pregnancy & Cycle

Pregnancy Conception Calculator

Estimate conception and fertile-window dates from a due date or last menstrual period.

  • Checked formula
  • Private in your browser
  • No signup
Calculator inputs

Enter your values

Result

Your calculation

Estimated conception date
Sunday, February 15, 2026
Likely fertile window
Tuesday, February 10, 2026 to Monday, February 16, 2026
Implantation window estimate
Saturday, February 21, 2026 to Friday, February 27, 2026

Ovulation and conception timing vary. Dating based on clinical ultrasound may be more reliable.

How to use this calculator

  1. Enter current measurements as accurately as practical.
  2. Calculate to see the estimate, range, and method details.
  3. Use the result as context, and discuss health decisions with a qualified clinician.

Use the result with context

Health results are educational estimates, not a diagnosis or treatment recommendation. A qualified clinician can interpret measurements in the context of your health.