Pregnancy Due Date Calculator

Client-side, privacy-first calculator. Supports LMP, Conception date, Ultrasound, IVF (transfer) and irregular cycles. Results are estimates — consult a clinician for definitive dating.

Calculation mode

Choose how you want to calculate the estimated due date.

First day of last menstrual period (LMP)

Average cycle length (days)

Used to adjust for irregular cycles (28 = standard).

Notes: This is an estimate. The most accurate dating is usually by first-trimester ultrasound. Calculations are performed in your browser and data is not sent to any server unless you choose to email or save.