Gestational Age Weeks Calculator
Convert days since the first day of the last menstrual period into gestational weeks and decimal weeks.
Gestational Age Weeks measurements
Enter your values, then calculate.
Result
How to calculate gestational age weeks
Convert an elapsed day count from the first day of the last menstrual period into gestational weeks.
How the calculation works
Clinical gestational age is commonly counted from the first day of the last menstrual period; dividing elapsed days by seven expresses that interval in weeks.
Example
One hundred twelve days since LMP equals 16 weeks.
Frequently asked questions
Is this a medical diagnosis?
No. It is a date-interval conversion and does not replace ultrasound dating or prenatal care.
Gestational Age Weeks Calculator
Clinical gestational age is commonly counted from the first day of the last menstrual period; dividing elapsed days by seven expresses that interval in weeks.
Let's understand your gestational age weeks result.
Calculate a result above and this guide will help you interpret it using this calculator's own formula and explanation.
Pro Tips for Gestational Age Weeks
- Use the first day of the last menstrual period as day zero.
- Confirm dating with a qualified clinician, especially when cycles are irregular.
Common Gestational Age Weeks Mistakes to Avoid
- Counting from conception rather than LMP usually makes the entered age about two weeks too low.
When to Use This Calculator
Convert an elapsed day count from the first day of the last menstrual period into gestational weeks.