Health & Fitness
Pregnancy Due Date Calculator
Estimate your due date and current week from your last period.
How this pregnancy due date calculator works
The pregnancy due date calculator takes the numbers you enter and applies a standard formula for this kind of calculation, showing the result instantly with no page reload. Estimate your due date and current week from your last period.
Everything runs client-side in JavaScript, so your inputs never leave your device — there's no server, no account and no tracking involved in getting your answer.
Frequently asked questions
This uses Naegele's rule: 280 days (40 weeks) from the first day of your last menstrual period, assuming a typical 28-day cycle. Your doctor's ultrasound-based estimate may differ slightly.