Pregnancy Calculator
Estimate gestational age and due date from your last period, with weekly insights.
What is Pregnancy Calculator
Enter the first day of your last period to get the estimated due date (Naegele's +280-day rule), current gestational week and trimester. Weekly tabs show the baby's size, weight and length, changes for mom, practical tips, a prenatal checkup schedule and nutrition notes for the 40-week journey.
How to use Pregnancy Calculator
- Enter the first day of your last menstrual period
- Calculate to see due date, current week and trimester
- Explore the weekly tabs for development notes and checkup suggestions
Frequently asked questions
Can this replace prenatal visits?
No — the weekly information is general reference only and cannot replace examination or advice from your doctor.
How accurate is the due date?
It is the standard 40-week estimate — only about 5% of babies arrive exactly on the EDD, and most births fall within two weeks on either side. Use it for planning, not scheduling.
How are the trimesters split?
Weeks 1–13 are the first trimester, 14–27 the second and 28 to delivery the third. The page marks your current stage from the computed gestational week.
Is the fetal development data personalized?
No — size, weight, checkup and nutrition entries are built-in general reference values, not tailored to your situation. Always confirm with your prenatal care provider.
Is Pregnancy Calculator free?
Pregnancy Calculator is completely free — open the page and use every feature with no hidden charges.
Do I need to download or install Pregnancy Calculator?
No download or installation is needed. It is an online tool that runs in the browser on your phone, tablet and computer.
Do I need an account to use Pregnancy Calculator?
No. Use the tool right away — no account or sign-in required.
Does Pregnancy Calculator work on mobile?
Yes. The page is fully responsive and works on phones, tablets and desktop browsers.