Pregnancy Calculator
Calculate your due date, trimester, and baby's growth.
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Quick Tip
Your due date is calculated by adding 280 days (40 weeks) to the first day of your last menstrual period.
Calculation History
| Date | LMP Used | Est. Due Date | Weeks |
|---|---|---|---|
| Your recent calculations will appear here. | |||
About This Pregnancy Calculator
Welcome to our free Pregnancy Calculator. This tool helps expecting mothers estimate their due date based on their Last Menstrual Period (LMP). Knowing your due date is the first step in tracking your pregnancy journey, scheduling prenatal appointments, and monitoring your baby's development week by week.
How is Due Date Calculated?
Our calculator uses Naegele's Rule, which is the standard method used by doctors and OB-GYNs worldwide.
- We take the first day of your Last Menstrual Period (LMP).
- We add 280 days (40 weeks) to that date.
- We adjust for your personal cycle length (if different from the standard 28 days).
Understanding the Trimesters
Pregnancy is divided into three stages called trimesters:
- First Trimester: Weeks 1 to 12. The baby's body structure and organ systems develop.
- Second Trimester: Weeks 13 to 26. Often called the "honeymoon phase," you may feel the baby move.
- Third Trimester: Weeks 27 to 40. The baby grows significantly in weight and prepares for birth.
Frequently Asked Questions (FAQ)
Can a pregnancy calculator be wrong?
Yes, it is an estimation. Only about 5% of babies are born on their exact due date. Most are born within two weeks before or after.
What if my cycle is not 28 days?
Our advanced tool allows you to adjust the cycle length. If your cycle is longer, your due date will be later. If shorter, it will be earlier.