What is Gestational Age Calculator?
A gestational age calculator helps determine pregnancy progress and due date. This essential tool estimates fetal age using the last menstrual period (LMP) or ultrasound data. Accurate pregnancy dating is crucial for monitoring fetal development, scheduling prenatal tests, and preparing for delivery. Our calculator follows standard obstetric guidelines to provide reliable results for expecting parents and healthcare providers.
Pregnancy Due Date Calculator
Gestational Age Formula
The standard calculation uses Naegele's Rule:
Due Date = LMP + 280 days
Gestational Age = Current Date - LMP Date (in weeks)
How to Use This Calculator
Enter your Last Menstrual Period (LMP) date in the calendar widget. Click calculate to instantly see your estimated due date and current pregnancy week. Our calculator automatically accounts for average cycle length and provides results based on standard obstetric practice. Regular prenatal care should always accompany calculator results.
Gestational Age Reference Table
| Trimester | Weeks | Key Developments |
|---|---|---|
| First | 1-12 | Organ formation, heartbeat begins |
| Second | 13-26 | Movement felt, sex visible |
| Third | 27-40 | Rapid growth, lung maturation |
Pros and Cons
Advantages:
- Quick and easy pregnancy dating
- Standardized calculation method
- Helps plan prenatal care
- Reduces estimation errors
- Accessible anytime
Limitations:
- Assumes regular 28-day cycles
- Doesn't account for ovulation variations
- Not a substitute for ultrasound
- Requires accurate LMP recall
- Doesn't predict actual delivery date