Pregnancy Calculator Due Date & Pregnancy Weeks
Calculate your estimated pregnancy due date, gestational age, conception date, trimester, days remaining, and pregnancy progress using your last menstrual period and cycle length.
A free online pregnancy due date calculator designed to provide a quick pregnancy timeline estimate from your LMP date.
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Pregnancy Calculator
Estimate your pregnancy dates
Free Pregnancy Due Date Calculator
A pregnancy calculator can provide an estimated due date and pregnancy timeline based on the first day of your last menstrual period. It can also estimate gestational age, conception timing, trimester, and the approximate number of days remaining.
Enter your LMP date and average menstrual cycle length to get an estimated pregnancy due date and other useful pregnancy timeline information.
Pregnancy Calculator Features
How to Use the Pregnancy Calculator
Enter your LMP date
Select the first day of your most recent menstrual period.
Enter your cycle length
Enter your average menstrual cycle length. The default is 28 days.
Calculate your pregnancy dates
Click Calculate Pregnancy to process the information.
Review your results
See your estimated due date, pregnancy weeks, conception date, trimester, progress, and milestones.
Pregnancy Due Date Formula
Estimated Due Date ≈ LMP + 280 days + (Cycle Length − 28 days)
This is an estimate based on the last menstrual period and the cycle length entered into the calculator.
Frequently Asked Questions
How is the estimated due date calculated?
The calculator starts with the first day of the last menstrual period and uses an estimated 280-day pregnancy period, with an adjustment based on the cycle length entered.
Why does menstrual cycle length affect the due date?
The standard calculation assumes a 28-day menstrual cycle. A different cycle length can shift the estimated timing, so the calculator applies a cycle-length adjustment.
What is gestational age?
Gestational age is the estimated length of pregnancy, generally measured from the first day of the last menstrual period.
Can this calculator predict the exact delivery date?
No. The calculated due date is an estimate. Actual delivery can occur before or after the estimated date.
What if I do not know my last menstrual period?
This calculator requires an LMP date. If you do not know the date, a qualified healthcare professional can use other methods to help estimate pregnancy dating.
Important Information
This pregnancy calculator provides an estimate for informational purposes only. Pregnancy dating can vary, and the actual due date may differ. This tool is not a substitute for professional medical advice, diagnosis, or care. Speak with a qualified healthcare professional for personalized pregnancy and prenatal care.
Calculate Your Estimated Due Date
Enter your last menstrual period and cycle length to estimate your pregnancy due date, gestational age, conception date, trimester, and pregnancy progress.
Calculate Pregnancy